chore: Update discovery artifacts (#1195)

* chore(accesscontextmanager): update the api
* chore(adexchangebuyer2): update the api
* chore(admin): update the api
* chore(alertcenter): update the api
* chore(analyticsadmin): update the api
* chore(analyticsdata): update the api
* chore(androidmanagement): update the api
* chore(apigateway): update the api
* chore(apigee): update the api
* chore(appengine): update the api
* chore(area120tables): update the api
* chore(artifactregistry): update the api
* chore(bigquery): update the api
* chore(bigqueryconnection): update the api
* chore(bigqueryreservation): update the api
* chore(billingbudgets): update the api
* chore(binaryauthorization): update the api
* chore(blogger): update the api
* chore(calendar): update the api
* chore(chat): update the api
* chore(cloudasset): update the api
* chore(cloudbuild): update the api
* chore(cloudfunctions): update the api
* chore(cloudidentity): update the api
* chore(cloudkms): update the api
* chore(cloudresourcemanager): update the api
* chore(cloudscheduler): update the api
* chore(cloudtasks): update the api
* chore(composer): update the api
* chore(compute): update the api
* chore(container): update the api
* chore(containeranalysis): update the api
* chore(content): update the api
* chore(datacatalog): update the api
* chore(dataflow): update the api
* chore(datafusion): update the api
* chore(datamigration): update the api
* chore(dataproc): update the api
* chore(deploymentmanager): update the api
* chore(dialogflow): update the api
* chore(displayvideo): update the api
* chore(dlp): update the api
* chore(dns): update the api
* chore(documentai): update the api
* chore(eventarc): update the api
* chore(file): update the api
* chore(firebaseml): update the api
* chore(games): update the api
* chore(gameservices): update the api
* chore(genomics): update the api
* chore(healthcare): update the api
* chore(homegraph): update the api
* chore(iam): update the api
* chore(iap): update the api
* chore(jobs): update the api
* chore(lifesciences): update the api
* chore(localservices): update the api
* chore(managedidentities): update the api
* chore(manufacturers): update the api
* chore(memcache): update the api
* chore(ml): update the api
* chore(monitoring): update the api
* chore(notebooks): update the api
* chore(osconfig): update the api
* chore(pagespeedonline): update the api
* chore(people): update the api
* chore(privateca): update the api
* chore(prod_tt_sasportal): update the api
* chore(pubsub): update the api
* chore(pubsublite): update the api
* chore(recommender): update the api
* chore(remotebuildexecution): update the api
* chore(reseller): update the api
* chore(run): update the api
* chore(safebrowsing): update the api
* chore(sasportal): update the api
* chore(searchconsole): update the api
* chore(secretmanager): update the api
* chore(securitycenter): update the api
* chore(serviceconsumermanagement): update the api
* chore(servicecontrol): update the api
* chore(servicenetworking): update the api
* chore(serviceusage): update the api
* chore(sheets): update the api
* chore(slides): update the api
* chore(spanner): update the api
* chore(speech): update the api
* chore(sqladmin): update the api
* chore(storage): update the api
* chore(storagetransfer): update the api
* chore(sts): update the api
* chore(tagmanager): update the api
* chore(testing): update the api
* chore(toolresults): update the api
* chore(transcoder): update the api
* chore(vectortile): update the api
* chore(videointelligence): update the api
* chore(vision): update the api
* chore(webmasters): update the api
* chore(workflowexecutions): update the api
* chore(youtube): update the api
diff --git a/docs/dyn/remotebuildexecution_v2.actionResults.html b/docs/dyn/remotebuildexecution_v2.actionResults.html
index 1b0af2c..9362027 100644
--- a/docs/dyn/remotebuildexecution_v2.actionResults.html
+++ b/docs/dyn/remotebuildexecution_v2.actionResults.html
@@ -79,10 +79,10 @@
 <p class="firstline">Close httplib2 connections.</p>
 <p class="toc_element">
   <code><a href="#get">get(instanceName, hash, sizeBytes, inlineOutputFiles=None, inlineStderr=None, inlineStdout=None, x__xgafv=None)</a></code></p>
-<p class="firstline">Retrieve a cached execution result. Implementations SHOULD ensure that any blobs referenced from the ContentAddressableStorage are available at the time of returning the ActionResult and will be for some period of time afterwards. The TTLs of the referenced blobs SHOULD be increased if necessary and applicable. Errors: * `NOT_FOUND`: The requested `ActionResult` is not in the cache.</p>
+<p class="firstline">Retrieve a cached execution result. Implementations SHOULD ensure that any blobs referenced from the ContentAddressableStorage are available at the time of returning the ActionResult and will be for some period of time afterwards. The lifetimes of the referenced blobs SHOULD be increased if necessary and applicable. Errors: * `NOT_FOUND`: The requested `ActionResult` is not in the cache.</p>
 <p class="toc_element">
   <code><a href="#update">update(instanceName, hash, sizeBytes, body=None, resultsCachePolicy_priority=None, x__xgafv=None)</a></code></p>
-<p class="firstline">Upload a new execution result. In order to allow the server to perform access control based on the type of action, and to assist with client debugging, the client MUST first upload the Action that produced the result, along with its Command, into the `ContentAddressableStorage`. Errors: * `INVALID_ARGUMENT`: One or more arguments are invalid. * `FAILED_PRECONDITION`: One or more errors occurred in updating the action result, such as a missing command or action. * `RESOURCE_EXHAUSTED`: There is insufficient storage space to add the entry to the cache.</p>
+<p class="firstline">Upload a new execution result. In order to allow the server to perform access control based on the type of action, and to assist with client debugging, the client MUST first upload the Action that produced the result, along with its Command, into the `ContentAddressableStorage`. Server implementations MAY modify the `UpdateActionResultRequest.action_result` and return an equivalent value. Errors: * `INVALID_ARGUMENT`: One or more arguments are invalid. * `FAILED_PRECONDITION`: One or more errors occurred in updating the action result, such as a missing command or action. * `RESOURCE_EXHAUSTED`: There is insufficient storage space to add the entry to the cache.</p>
 <h3>Method Details</h3>
 <div class="method">
     <code class="details" id="close">close()</code>
@@ -91,13 +91,13 @@
 
 <div class="method">
     <code class="details" id="get">get(instanceName, hash, sizeBytes, inlineOutputFiles=None, inlineStderr=None, inlineStdout=None, x__xgafv=None)</code>
-  <pre>Retrieve a cached execution result. Implementations SHOULD ensure that any blobs referenced from the ContentAddressableStorage are available at the time of returning the ActionResult and will be for some period of time afterwards. The TTLs of the referenced blobs SHOULD be increased if necessary and applicable. Errors: * `NOT_FOUND`: The requested `ActionResult` is not in the cache.
+  <pre>Retrieve a cached execution result. Implementations SHOULD ensure that any blobs referenced from the ContentAddressableStorage are available at the time of returning the ActionResult and will be for some period of time afterwards. The lifetimes of the referenced blobs SHOULD be increased if necessary and applicable. Errors: * `NOT_FOUND`: The requested `ActionResult` is not in the cache.
 
 Args:
   instanceName: string, The instance of the execution system to operate against. A server may support multiple instances of the execution system (with their own workers, storage, caches, etc.). The server MAY require use of this field to select between them in an implementation-defined fashion, otherwise it can be omitted. (required)
   hash: string, The hash. In the case of SHA-256, it will always be a lowercase hex string exactly 64 characters long. (required)
   sizeBytes: string, The size of the blob, in bytes. (required)
-  inlineOutputFiles: string, A hint to the server to inline the contents of the listed output files. Each path needs to exactly match one path in `output_files` in the Command message. (repeated)
+  inlineOutputFiles: string, A hint to the server to inline the contents of the listed output files. Each path needs to exactly match one file path in either `output_paths` or `output_files` (DEPRECATED since v2.1) in the Command message. (repeated)
   inlineStderr: boolean, A hint to the server to request inlining stderr in the ActionResult message.
   inlineStdout: boolean, A hint to the server to request inlining stdout in the ActionResult message.
   x__xgafv: string, V1 error format.
@@ -108,8 +108,13 @@
 Returns:
   An object of the form:
 
-    { # An ActionResult represents the result of an Action being run.
+    { # An ActionResult represents the result of an Action being run. It is advised that at least one field (for example `ActionResult.execution_metadata.Worker`) have a non-default value, to ensure that the serialized value is non-empty, which can then be used as a basic data sanity check.
   &quot;executionMetadata&quot;: { # ExecutedActionMetadata contains details about a completed execution. # The details of the execution that originally produced this result.
+    &quot;auxiliaryMetadata&quot;: [ # Details that are specific to the kind of worker used. For example, on POSIX-like systems this could contain a message with getrusage(2) statistics.
+      {
+        &quot;a_key&quot;: &quot;&quot;, # Properties of the object. Contains field @type with type URL.
+      },
+    ],
     &quot;executionCompletedTimestamp&quot;: &quot;A String&quot;, # When the worker completed executing the action command.
     &quot;executionStartTimestamp&quot;: &quot;A String&quot;, # When the worker started executing the action command.
     &quot;inputFetchCompletedTimestamp&quot;: &quot;A String&quot;, # When the worker finished fetching action inputs.
@@ -133,26 +138,34 @@
   ],
   &quot;outputDirectorySymlinks&quot;: [ # The output directories of the action that are symbolic links to other directories. Those may be links to other output directories, or input directories, or even absolute paths outside of the working directory, if the server supports SymlinkAbsolutePathStrategy.ALLOWED. For each output directory requested in the `output_directories` field of the Action, if the directory existed after the action completed, a single entry will be present either in this field, or in the `output_directories` field, if the directory was not a symbolic link. If an output of the same name was found, but was a symbolic link to a file instead of a directory, the server will return a FAILED_PRECONDITION. If the action does not produce the requested output, then that output will be omitted from the list. The server is free to arrange the output list as desired; clients MUST NOT assume that the output list is sorted. DEPRECATED as of v2.1. Servers that wish to be compatible with v2.0 API should still populate this field in addition to `output_symlinks`.
     { # An `OutputSymlink` is similar to a Symlink, but it is used as an output in an `ActionResult`. `OutputSymlink` is binary-compatible with `SymlinkNode`.
-      &quot;nodeProperties&quot;: [ # The supported node properties of the OutputSymlink, if requested by the Action.
-        { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
-          &quot;name&quot;: &quot;A String&quot;, # The property name.
-          &quot;value&quot;: &quot;A String&quot;, # The property value.
-        },
-      ],
+      &quot;nodeProperties&quot;: { # Node properties for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the properties that it accepts.
+        &quot;mtime&quot;: &quot;A String&quot;, # The file&#x27;s last modification timestamp.
+        &quot;properties&quot;: [ # A list of string-based NodeProperties.
+          { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
+            &quot;name&quot;: &quot;A String&quot;, # The property name.
+            &quot;value&quot;: &quot;A String&quot;, # The property value.
+          },
+        ],
+        &quot;unixMode&quot;: 42, # The UNIX file mode, e.g., 0755.
+      },
       &quot;path&quot;: &quot;A String&quot;, # The full path of the symlink relative to the working directory, including the filename. The path separator is a forward slash `/`. Since this is a relative path, it MUST NOT begin with a leading forward slash.
-      &quot;target&quot;: &quot;A String&quot;, # The target path of the symlink. The path separator is a forward slash `/`. The target path can be relative to the parent directory of the symlink or it can be an absolute path starting with `/`. Support for absolute paths can be checked using the Capabilities API. The canonical form forbids the substrings `/./` and `//` in the target path. `..` components are allowed anywhere in the target path.
+      &quot;target&quot;: &quot;A String&quot;, # The target path of the symlink. The path separator is a forward slash `/`. The target path can be relative to the parent directory of the symlink or it can be an absolute path starting with `/`. Support for absolute paths can be checked using the Capabilities API. `..` components are allowed anywhere in the target path.
     },
   ],
   &quot;outputFileSymlinks&quot;: [ # The output files of the action that are symbolic links to other files. Those may be links to other output files, or input files, or even absolute paths outside of the working directory, if the server supports SymlinkAbsolutePathStrategy.ALLOWED. For each output file requested in the `output_files` or `output_paths` field of the Action, if the corresponding file existed after the action completed, a single entry will be present either in this field, or in the `output_files` field, if the file was not a symbolic link. If an output symbolic link of the same name as listed in `output_files` of the Command was found, but its target type was not a regular file, the server will return a FAILED_PRECONDITION. If the action does not produce the requested output, then that output will be omitted from the list. The server is free to arrange the output list as desired; clients MUST NOT assume that the output list is sorted. DEPRECATED as of v2.1. Servers that wish to be compatible with v2.0 API should still populate this field in addition to `output_symlinks`.
     { # An `OutputSymlink` is similar to a Symlink, but it is used as an output in an `ActionResult`. `OutputSymlink` is binary-compatible with `SymlinkNode`.
-      &quot;nodeProperties&quot;: [ # The supported node properties of the OutputSymlink, if requested by the Action.
-        { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
-          &quot;name&quot;: &quot;A String&quot;, # The property name.
-          &quot;value&quot;: &quot;A String&quot;, # The property value.
-        },
-      ],
+      &quot;nodeProperties&quot;: { # Node properties for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the properties that it accepts.
+        &quot;mtime&quot;: &quot;A String&quot;, # The file&#x27;s last modification timestamp.
+        &quot;properties&quot;: [ # A list of string-based NodeProperties.
+          { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
+            &quot;name&quot;: &quot;A String&quot;, # The property name.
+            &quot;value&quot;: &quot;A String&quot;, # The property value.
+          },
+        ],
+        &quot;unixMode&quot;: 42, # The UNIX file mode, e.g., 0755.
+      },
       &quot;path&quot;: &quot;A String&quot;, # The full path of the symlink relative to the working directory, including the filename. The path separator is a forward slash `/`. Since this is a relative path, it MUST NOT begin with a leading forward slash.
-      &quot;target&quot;: &quot;A String&quot;, # The target path of the symlink. The path separator is a forward slash `/`. The target path can be relative to the parent directory of the symlink or it can be an absolute path starting with `/`. Support for absolute paths can be checked using the Capabilities API. The canonical form forbids the substrings `/./` and `//` in the target path. `..` components are allowed anywhere in the target path.
+      &quot;target&quot;: &quot;A String&quot;, # The target path of the symlink. The path separator is a forward slash `/`. The target path can be relative to the parent directory of the symlink or it can be an absolute path starting with `/`. Support for absolute paths can be checked using the Capabilities API. `..` components are allowed anywhere in the target path.
     },
   ],
   &quot;outputFiles&quot;: [ # The output files of the action. For each output file requested in the `output_files` or `output_paths` field of the Action, if the corresponding file existed after the action completed, a single entry will be present either in this field, or the `output_file_symlinks` field if the file was a symbolic link to another file (`output_symlinks` field after v2.1). If an output listed in `output_files` was found, but was a directory rather than a regular file, the server will return a FAILED_PRECONDITION. If the action does not produce the requested output, then that output will be omitted from the list. The server is free to arrange the output list as desired; clients MUST NOT assume that the output list is sorted.
@@ -163,25 +176,33 @@
         &quot;sizeBytes&quot;: &quot;A String&quot;, # The size of the blob, in bytes.
       },
       &quot;isExecutable&quot;: True or False, # True if file is executable, false otherwise.
-      &quot;nodeProperties&quot;: [ # The supported node properties of the OutputFile, if requested by the Action.
-        { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
-          &quot;name&quot;: &quot;A String&quot;, # The property name.
-          &quot;value&quot;: &quot;A String&quot;, # The property value.
-        },
-      ],
+      &quot;nodeProperties&quot;: { # Node properties for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the properties that it accepts.
+        &quot;mtime&quot;: &quot;A String&quot;, # The file&#x27;s last modification timestamp.
+        &quot;properties&quot;: [ # A list of string-based NodeProperties.
+          { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
+            &quot;name&quot;: &quot;A String&quot;, # The property name.
+            &quot;value&quot;: &quot;A String&quot;, # The property value.
+          },
+        ],
+        &quot;unixMode&quot;: 42, # The UNIX file mode, e.g., 0755.
+      },
       &quot;path&quot;: &quot;A String&quot;, # The full path of the file relative to the working directory, including the filename. The path separator is a forward slash `/`. Since this is a relative path, it MUST NOT begin with a leading forward slash.
     },
   ],
   &quot;outputSymlinks&quot;: [ # New in v2.1: this field will only be populated if the command `output_paths` field was used, and not the pre v2.1 `output_files` or `output_directories` fields. The output paths of the action that are symbolic links to other paths. Those may be links to other outputs, or inputs, or even absolute paths outside of the working directory, if the server supports SymlinkAbsolutePathStrategy.ALLOWED. A single entry for each output requested in `output_paths` field of the Action, if the corresponding path existed after the action completed and was a symbolic link. If the action does not produce a requested output, then that output will be omitted from the list. The server is free to arrange the output list as desired; clients MUST NOT assume that the output list is sorted.
     { # An `OutputSymlink` is similar to a Symlink, but it is used as an output in an `ActionResult`. `OutputSymlink` is binary-compatible with `SymlinkNode`.
-      &quot;nodeProperties&quot;: [ # The supported node properties of the OutputSymlink, if requested by the Action.
-        { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
-          &quot;name&quot;: &quot;A String&quot;, # The property name.
-          &quot;value&quot;: &quot;A String&quot;, # The property value.
-        },
-      ],
+      &quot;nodeProperties&quot;: { # Node properties for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the properties that it accepts.
+        &quot;mtime&quot;: &quot;A String&quot;, # The file&#x27;s last modification timestamp.
+        &quot;properties&quot;: [ # A list of string-based NodeProperties.
+          { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
+            &quot;name&quot;: &quot;A String&quot;, # The property name.
+            &quot;value&quot;: &quot;A String&quot;, # The property value.
+          },
+        ],
+        &quot;unixMode&quot;: 42, # The UNIX file mode, e.g., 0755.
+      },
       &quot;path&quot;: &quot;A String&quot;, # The full path of the symlink relative to the working directory, including the filename. The path separator is a forward slash `/`. Since this is a relative path, it MUST NOT begin with a leading forward slash.
-      &quot;target&quot;: &quot;A String&quot;, # The target path of the symlink. The path separator is a forward slash `/`. The target path can be relative to the parent directory of the symlink or it can be an absolute path starting with `/`. Support for absolute paths can be checked using the Capabilities API. The canonical form forbids the substrings `/./` and `//` in the target path. `..` components are allowed anywhere in the target path.
+      &quot;target&quot;: &quot;A String&quot;, # The target path of the symlink. The path separator is a forward slash `/`. The target path can be relative to the parent directory of the symlink or it can be an absolute path starting with `/`. Support for absolute paths can be checked using the Capabilities API. `..` components are allowed anywhere in the target path.
     },
   ],
   &quot;stderrDigest&quot;: { # A content digest. A digest for a given blob consists of the size of the blob and its hash. The hash algorithm to use is defined by the server. The size is considered to be an integral part of the digest and cannot be separated. That is, even if the `hash` field is correctly specified but `size_bytes` is not, the server MUST reject the request. The reason for including the size in the digest is as follows: in a great many cases, the server needs to know the size of the blob it is about to work with prior to starting an operation with it, such as flattening Merkle tree structures or streaming it to a worker. Technically, the server could implement a separate metadata store, but this results in a significantly more complicated implementation as opposed to having the client specify the size up-front (or storing the size along with the digest in every message where digests are embedded). This does mean that the API leaks some implementation details of (what we consider to be) a reasonable server implementation, but we consider this to be a worthwhile tradeoff. When a `Digest` is used to refer to a proto message, it always refers to the message in binary encoded form. To ensure consistent hashing, clients and servers MUST ensure that they serialize messages according to the following rules, even if there are alternate valid encodings for the same message: * Fields are serialized in tag order. * There are no unknown fields. * There are no duplicate fields. * Fields are serialized according to the default semantics for their type. Most protocol buffer implementations will always follow these rules when serializing, but care should be taken to avoid shortcuts. For instance, concatenating two messages to merge them may produce duplicate fields. # The digest for a blob containing the standard error of the action, which can be retrieved from the ContentAddressableStorage.
@@ -199,7 +220,7 @@
 
 <div class="method">
     <code class="details" id="update">update(instanceName, hash, sizeBytes, body=None, resultsCachePolicy_priority=None, x__xgafv=None)</code>
-  <pre>Upload a new execution result. In order to allow the server to perform access control based on the type of action, and to assist with client debugging, the client MUST first upload the Action that produced the result, along with its Command, into the `ContentAddressableStorage`. Errors: * `INVALID_ARGUMENT`: One or more arguments are invalid. * `FAILED_PRECONDITION`: One or more errors occurred in updating the action result, such as a missing command or action. * `RESOURCE_EXHAUSTED`: There is insufficient storage space to add the entry to the cache.
+  <pre>Upload a new execution result. In order to allow the server to perform access control based on the type of action, and to assist with client debugging, the client MUST first upload the Action that produced the result, along with its Command, into the `ContentAddressableStorage`. Server implementations MAY modify the `UpdateActionResultRequest.action_result` and return an equivalent value. Errors: * `INVALID_ARGUMENT`: One or more arguments are invalid. * `FAILED_PRECONDITION`: One or more errors occurred in updating the action result, such as a missing command or action. * `RESOURCE_EXHAUSTED`: There is insufficient storage space to add the entry to the cache.
 
 Args:
   instanceName: string, The instance of the execution system to operate against. A server may support multiple instances of the execution system (with their own workers, storage, caches, etc.). The server MAY require use of this field to select between them in an implementation-defined fashion, otherwise it can be omitted. (required)
@@ -208,8 +229,13 @@
   body: object, The request body.
     The object takes the form of:
 
-{ # An ActionResult represents the result of an Action being run.
+{ # An ActionResult represents the result of an Action being run. It is advised that at least one field (for example `ActionResult.execution_metadata.Worker`) have a non-default value, to ensure that the serialized value is non-empty, which can then be used as a basic data sanity check.
   &quot;executionMetadata&quot;: { # ExecutedActionMetadata contains details about a completed execution. # The details of the execution that originally produced this result.
+    &quot;auxiliaryMetadata&quot;: [ # Details that are specific to the kind of worker used. For example, on POSIX-like systems this could contain a message with getrusage(2) statistics.
+      {
+        &quot;a_key&quot;: &quot;&quot;, # Properties of the object. Contains field @type with type URL.
+      },
+    ],
     &quot;executionCompletedTimestamp&quot;: &quot;A String&quot;, # When the worker completed executing the action command.
     &quot;executionStartTimestamp&quot;: &quot;A String&quot;, # When the worker started executing the action command.
     &quot;inputFetchCompletedTimestamp&quot;: &quot;A String&quot;, # When the worker finished fetching action inputs.
@@ -233,26 +259,34 @@
   ],
   &quot;outputDirectorySymlinks&quot;: [ # The output directories of the action that are symbolic links to other directories. Those may be links to other output directories, or input directories, or even absolute paths outside of the working directory, if the server supports SymlinkAbsolutePathStrategy.ALLOWED. For each output directory requested in the `output_directories` field of the Action, if the directory existed after the action completed, a single entry will be present either in this field, or in the `output_directories` field, if the directory was not a symbolic link. If an output of the same name was found, but was a symbolic link to a file instead of a directory, the server will return a FAILED_PRECONDITION. If the action does not produce the requested output, then that output will be omitted from the list. The server is free to arrange the output list as desired; clients MUST NOT assume that the output list is sorted. DEPRECATED as of v2.1. Servers that wish to be compatible with v2.0 API should still populate this field in addition to `output_symlinks`.
     { # An `OutputSymlink` is similar to a Symlink, but it is used as an output in an `ActionResult`. `OutputSymlink` is binary-compatible with `SymlinkNode`.
-      &quot;nodeProperties&quot;: [ # The supported node properties of the OutputSymlink, if requested by the Action.
-        { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
-          &quot;name&quot;: &quot;A String&quot;, # The property name.
-          &quot;value&quot;: &quot;A String&quot;, # The property value.
-        },
-      ],
+      &quot;nodeProperties&quot;: { # Node properties for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the properties that it accepts.
+        &quot;mtime&quot;: &quot;A String&quot;, # The file&#x27;s last modification timestamp.
+        &quot;properties&quot;: [ # A list of string-based NodeProperties.
+          { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
+            &quot;name&quot;: &quot;A String&quot;, # The property name.
+            &quot;value&quot;: &quot;A String&quot;, # The property value.
+          },
+        ],
+        &quot;unixMode&quot;: 42, # The UNIX file mode, e.g., 0755.
+      },
       &quot;path&quot;: &quot;A String&quot;, # The full path of the symlink relative to the working directory, including the filename. The path separator is a forward slash `/`. Since this is a relative path, it MUST NOT begin with a leading forward slash.
-      &quot;target&quot;: &quot;A String&quot;, # The target path of the symlink. The path separator is a forward slash `/`. The target path can be relative to the parent directory of the symlink or it can be an absolute path starting with `/`. Support for absolute paths can be checked using the Capabilities API. The canonical form forbids the substrings `/./` and `//` in the target path. `..` components are allowed anywhere in the target path.
+      &quot;target&quot;: &quot;A String&quot;, # The target path of the symlink. The path separator is a forward slash `/`. The target path can be relative to the parent directory of the symlink or it can be an absolute path starting with `/`. Support for absolute paths can be checked using the Capabilities API. `..` components are allowed anywhere in the target path.
     },
   ],
   &quot;outputFileSymlinks&quot;: [ # The output files of the action that are symbolic links to other files. Those may be links to other output files, or input files, or even absolute paths outside of the working directory, if the server supports SymlinkAbsolutePathStrategy.ALLOWED. For each output file requested in the `output_files` or `output_paths` field of the Action, if the corresponding file existed after the action completed, a single entry will be present either in this field, or in the `output_files` field, if the file was not a symbolic link. If an output symbolic link of the same name as listed in `output_files` of the Command was found, but its target type was not a regular file, the server will return a FAILED_PRECONDITION. If the action does not produce the requested output, then that output will be omitted from the list. The server is free to arrange the output list as desired; clients MUST NOT assume that the output list is sorted. DEPRECATED as of v2.1. Servers that wish to be compatible with v2.0 API should still populate this field in addition to `output_symlinks`.
     { # An `OutputSymlink` is similar to a Symlink, but it is used as an output in an `ActionResult`. `OutputSymlink` is binary-compatible with `SymlinkNode`.
-      &quot;nodeProperties&quot;: [ # The supported node properties of the OutputSymlink, if requested by the Action.
-        { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
-          &quot;name&quot;: &quot;A String&quot;, # The property name.
-          &quot;value&quot;: &quot;A String&quot;, # The property value.
-        },
-      ],
+      &quot;nodeProperties&quot;: { # Node properties for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the properties that it accepts.
+        &quot;mtime&quot;: &quot;A String&quot;, # The file&#x27;s last modification timestamp.
+        &quot;properties&quot;: [ # A list of string-based NodeProperties.
+          { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
+            &quot;name&quot;: &quot;A String&quot;, # The property name.
+            &quot;value&quot;: &quot;A String&quot;, # The property value.
+          },
+        ],
+        &quot;unixMode&quot;: 42, # The UNIX file mode, e.g., 0755.
+      },
       &quot;path&quot;: &quot;A String&quot;, # The full path of the symlink relative to the working directory, including the filename. The path separator is a forward slash `/`. Since this is a relative path, it MUST NOT begin with a leading forward slash.
-      &quot;target&quot;: &quot;A String&quot;, # The target path of the symlink. The path separator is a forward slash `/`. The target path can be relative to the parent directory of the symlink or it can be an absolute path starting with `/`. Support for absolute paths can be checked using the Capabilities API. The canonical form forbids the substrings `/./` and `//` in the target path. `..` components are allowed anywhere in the target path.
+      &quot;target&quot;: &quot;A String&quot;, # The target path of the symlink. The path separator is a forward slash `/`. The target path can be relative to the parent directory of the symlink or it can be an absolute path starting with `/`. Support for absolute paths can be checked using the Capabilities API. `..` components are allowed anywhere in the target path.
     },
   ],
   &quot;outputFiles&quot;: [ # The output files of the action. For each output file requested in the `output_files` or `output_paths` field of the Action, if the corresponding file existed after the action completed, a single entry will be present either in this field, or the `output_file_symlinks` field if the file was a symbolic link to another file (`output_symlinks` field after v2.1). If an output listed in `output_files` was found, but was a directory rather than a regular file, the server will return a FAILED_PRECONDITION. If the action does not produce the requested output, then that output will be omitted from the list. The server is free to arrange the output list as desired; clients MUST NOT assume that the output list is sorted.
@@ -263,25 +297,33 @@
         &quot;sizeBytes&quot;: &quot;A String&quot;, # The size of the blob, in bytes.
       },
       &quot;isExecutable&quot;: True or False, # True if file is executable, false otherwise.
-      &quot;nodeProperties&quot;: [ # The supported node properties of the OutputFile, if requested by the Action.
-        { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
-          &quot;name&quot;: &quot;A String&quot;, # The property name.
-          &quot;value&quot;: &quot;A String&quot;, # The property value.
-        },
-      ],
+      &quot;nodeProperties&quot;: { # Node properties for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the properties that it accepts.
+        &quot;mtime&quot;: &quot;A String&quot;, # The file&#x27;s last modification timestamp.
+        &quot;properties&quot;: [ # A list of string-based NodeProperties.
+          { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
+            &quot;name&quot;: &quot;A String&quot;, # The property name.
+            &quot;value&quot;: &quot;A String&quot;, # The property value.
+          },
+        ],
+        &quot;unixMode&quot;: 42, # The UNIX file mode, e.g., 0755.
+      },
       &quot;path&quot;: &quot;A String&quot;, # The full path of the file relative to the working directory, including the filename. The path separator is a forward slash `/`. Since this is a relative path, it MUST NOT begin with a leading forward slash.
     },
   ],
   &quot;outputSymlinks&quot;: [ # New in v2.1: this field will only be populated if the command `output_paths` field was used, and not the pre v2.1 `output_files` or `output_directories` fields. The output paths of the action that are symbolic links to other paths. Those may be links to other outputs, or inputs, or even absolute paths outside of the working directory, if the server supports SymlinkAbsolutePathStrategy.ALLOWED. A single entry for each output requested in `output_paths` field of the Action, if the corresponding path existed after the action completed and was a symbolic link. If the action does not produce a requested output, then that output will be omitted from the list. The server is free to arrange the output list as desired; clients MUST NOT assume that the output list is sorted.
     { # An `OutputSymlink` is similar to a Symlink, but it is used as an output in an `ActionResult`. `OutputSymlink` is binary-compatible with `SymlinkNode`.
-      &quot;nodeProperties&quot;: [ # The supported node properties of the OutputSymlink, if requested by the Action.
-        { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
-          &quot;name&quot;: &quot;A String&quot;, # The property name.
-          &quot;value&quot;: &quot;A String&quot;, # The property value.
-        },
-      ],
+      &quot;nodeProperties&quot;: { # Node properties for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the properties that it accepts.
+        &quot;mtime&quot;: &quot;A String&quot;, # The file&#x27;s last modification timestamp.
+        &quot;properties&quot;: [ # A list of string-based NodeProperties.
+          { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
+            &quot;name&quot;: &quot;A String&quot;, # The property name.
+            &quot;value&quot;: &quot;A String&quot;, # The property value.
+          },
+        ],
+        &quot;unixMode&quot;: 42, # The UNIX file mode, e.g., 0755.
+      },
       &quot;path&quot;: &quot;A String&quot;, # The full path of the symlink relative to the working directory, including the filename. The path separator is a forward slash `/`. Since this is a relative path, it MUST NOT begin with a leading forward slash.
-      &quot;target&quot;: &quot;A String&quot;, # The target path of the symlink. The path separator is a forward slash `/`. The target path can be relative to the parent directory of the symlink or it can be an absolute path starting with `/`. Support for absolute paths can be checked using the Capabilities API. The canonical form forbids the substrings `/./` and `//` in the target path. `..` components are allowed anywhere in the target path.
+      &quot;target&quot;: &quot;A String&quot;, # The target path of the symlink. The path separator is a forward slash `/`. The target path can be relative to the parent directory of the symlink or it can be an absolute path starting with `/`. Support for absolute paths can be checked using the Capabilities API. `..` components are allowed anywhere in the target path.
     },
   ],
   &quot;stderrDigest&quot;: { # A content digest. A digest for a given blob consists of the size of the blob and its hash. The hash algorithm to use is defined by the server. The size is considered to be an integral part of the digest and cannot be separated. That is, even if the `hash` field is correctly specified but `size_bytes` is not, the server MUST reject the request. The reason for including the size in the digest is as follows: in a great many cases, the server needs to know the size of the blob it is about to work with prior to starting an operation with it, such as flattening Merkle tree structures or streaming it to a worker. Technically, the server could implement a separate metadata store, but this results in a significantly more complicated implementation as opposed to having the client specify the size up-front (or storing the size along with the digest in every message where digests are embedded). This does mean that the API leaks some implementation details of (what we consider to be) a reasonable server implementation, but we consider this to be a worthwhile tradeoff. When a `Digest` is used to refer to a proto message, it always refers to the message in binary encoded form. To ensure consistent hashing, clients and servers MUST ensure that they serialize messages according to the following rules, even if there are alternate valid encodings for the same message: * Fields are serialized in tag order. * There are no unknown fields. * There are no duplicate fields. * Fields are serialized according to the default semantics for their type. Most protocol buffer implementations will always follow these rules when serializing, but care should be taken to avoid shortcuts. For instance, concatenating two messages to merge them may produce duplicate fields. # The digest for a blob containing the standard error of the action, which can be retrieved from the ContentAddressableStorage.
@@ -305,8 +347,13 @@
 Returns:
   An object of the form:
 
-    { # An ActionResult represents the result of an Action being run.
+    { # An ActionResult represents the result of an Action being run. It is advised that at least one field (for example `ActionResult.execution_metadata.Worker`) have a non-default value, to ensure that the serialized value is non-empty, which can then be used as a basic data sanity check.
   &quot;executionMetadata&quot;: { # ExecutedActionMetadata contains details about a completed execution. # The details of the execution that originally produced this result.
+    &quot;auxiliaryMetadata&quot;: [ # Details that are specific to the kind of worker used. For example, on POSIX-like systems this could contain a message with getrusage(2) statistics.
+      {
+        &quot;a_key&quot;: &quot;&quot;, # Properties of the object. Contains field @type with type URL.
+      },
+    ],
     &quot;executionCompletedTimestamp&quot;: &quot;A String&quot;, # When the worker completed executing the action command.
     &quot;executionStartTimestamp&quot;: &quot;A String&quot;, # When the worker started executing the action command.
     &quot;inputFetchCompletedTimestamp&quot;: &quot;A String&quot;, # When the worker finished fetching action inputs.
@@ -330,26 +377,34 @@
   ],
   &quot;outputDirectorySymlinks&quot;: [ # The output directories of the action that are symbolic links to other directories. Those may be links to other output directories, or input directories, or even absolute paths outside of the working directory, if the server supports SymlinkAbsolutePathStrategy.ALLOWED. For each output directory requested in the `output_directories` field of the Action, if the directory existed after the action completed, a single entry will be present either in this field, or in the `output_directories` field, if the directory was not a symbolic link. If an output of the same name was found, but was a symbolic link to a file instead of a directory, the server will return a FAILED_PRECONDITION. If the action does not produce the requested output, then that output will be omitted from the list. The server is free to arrange the output list as desired; clients MUST NOT assume that the output list is sorted. DEPRECATED as of v2.1. Servers that wish to be compatible with v2.0 API should still populate this field in addition to `output_symlinks`.
     { # An `OutputSymlink` is similar to a Symlink, but it is used as an output in an `ActionResult`. `OutputSymlink` is binary-compatible with `SymlinkNode`.
-      &quot;nodeProperties&quot;: [ # The supported node properties of the OutputSymlink, if requested by the Action.
-        { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
-          &quot;name&quot;: &quot;A String&quot;, # The property name.
-          &quot;value&quot;: &quot;A String&quot;, # The property value.
-        },
-      ],
+      &quot;nodeProperties&quot;: { # Node properties for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the properties that it accepts.
+        &quot;mtime&quot;: &quot;A String&quot;, # The file&#x27;s last modification timestamp.
+        &quot;properties&quot;: [ # A list of string-based NodeProperties.
+          { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
+            &quot;name&quot;: &quot;A String&quot;, # The property name.
+            &quot;value&quot;: &quot;A String&quot;, # The property value.
+          },
+        ],
+        &quot;unixMode&quot;: 42, # The UNIX file mode, e.g., 0755.
+      },
       &quot;path&quot;: &quot;A String&quot;, # The full path of the symlink relative to the working directory, including the filename. The path separator is a forward slash `/`. Since this is a relative path, it MUST NOT begin with a leading forward slash.
-      &quot;target&quot;: &quot;A String&quot;, # The target path of the symlink. The path separator is a forward slash `/`. The target path can be relative to the parent directory of the symlink or it can be an absolute path starting with `/`. Support for absolute paths can be checked using the Capabilities API. The canonical form forbids the substrings `/./` and `//` in the target path. `..` components are allowed anywhere in the target path.
+      &quot;target&quot;: &quot;A String&quot;, # The target path of the symlink. The path separator is a forward slash `/`. The target path can be relative to the parent directory of the symlink or it can be an absolute path starting with `/`. Support for absolute paths can be checked using the Capabilities API. `..` components are allowed anywhere in the target path.
     },
   ],
   &quot;outputFileSymlinks&quot;: [ # The output files of the action that are symbolic links to other files. Those may be links to other output files, or input files, or even absolute paths outside of the working directory, if the server supports SymlinkAbsolutePathStrategy.ALLOWED. For each output file requested in the `output_files` or `output_paths` field of the Action, if the corresponding file existed after the action completed, a single entry will be present either in this field, or in the `output_files` field, if the file was not a symbolic link. If an output symbolic link of the same name as listed in `output_files` of the Command was found, but its target type was not a regular file, the server will return a FAILED_PRECONDITION. If the action does not produce the requested output, then that output will be omitted from the list. The server is free to arrange the output list as desired; clients MUST NOT assume that the output list is sorted. DEPRECATED as of v2.1. Servers that wish to be compatible with v2.0 API should still populate this field in addition to `output_symlinks`.
     { # An `OutputSymlink` is similar to a Symlink, but it is used as an output in an `ActionResult`. `OutputSymlink` is binary-compatible with `SymlinkNode`.
-      &quot;nodeProperties&quot;: [ # The supported node properties of the OutputSymlink, if requested by the Action.
-        { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
-          &quot;name&quot;: &quot;A String&quot;, # The property name.
-          &quot;value&quot;: &quot;A String&quot;, # The property value.
-        },
-      ],
+      &quot;nodeProperties&quot;: { # Node properties for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the properties that it accepts.
+        &quot;mtime&quot;: &quot;A String&quot;, # The file&#x27;s last modification timestamp.
+        &quot;properties&quot;: [ # A list of string-based NodeProperties.
+          { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
+            &quot;name&quot;: &quot;A String&quot;, # The property name.
+            &quot;value&quot;: &quot;A String&quot;, # The property value.
+          },
+        ],
+        &quot;unixMode&quot;: 42, # The UNIX file mode, e.g., 0755.
+      },
       &quot;path&quot;: &quot;A String&quot;, # The full path of the symlink relative to the working directory, including the filename. The path separator is a forward slash `/`. Since this is a relative path, it MUST NOT begin with a leading forward slash.
-      &quot;target&quot;: &quot;A String&quot;, # The target path of the symlink. The path separator is a forward slash `/`. The target path can be relative to the parent directory of the symlink or it can be an absolute path starting with `/`. Support for absolute paths can be checked using the Capabilities API. The canonical form forbids the substrings `/./` and `//` in the target path. `..` components are allowed anywhere in the target path.
+      &quot;target&quot;: &quot;A String&quot;, # The target path of the symlink. The path separator is a forward slash `/`. The target path can be relative to the parent directory of the symlink or it can be an absolute path starting with `/`. Support for absolute paths can be checked using the Capabilities API. `..` components are allowed anywhere in the target path.
     },
   ],
   &quot;outputFiles&quot;: [ # The output files of the action. For each output file requested in the `output_files` or `output_paths` field of the Action, if the corresponding file existed after the action completed, a single entry will be present either in this field, or the `output_file_symlinks` field if the file was a symbolic link to another file (`output_symlinks` field after v2.1). If an output listed in `output_files` was found, but was a directory rather than a regular file, the server will return a FAILED_PRECONDITION. If the action does not produce the requested output, then that output will be omitted from the list. The server is free to arrange the output list as desired; clients MUST NOT assume that the output list is sorted.
@@ -360,25 +415,33 @@
         &quot;sizeBytes&quot;: &quot;A String&quot;, # The size of the blob, in bytes.
       },
       &quot;isExecutable&quot;: True or False, # True if file is executable, false otherwise.
-      &quot;nodeProperties&quot;: [ # The supported node properties of the OutputFile, if requested by the Action.
-        { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
-          &quot;name&quot;: &quot;A String&quot;, # The property name.
-          &quot;value&quot;: &quot;A String&quot;, # The property value.
-        },
-      ],
+      &quot;nodeProperties&quot;: { # Node properties for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the properties that it accepts.
+        &quot;mtime&quot;: &quot;A String&quot;, # The file&#x27;s last modification timestamp.
+        &quot;properties&quot;: [ # A list of string-based NodeProperties.
+          { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
+            &quot;name&quot;: &quot;A String&quot;, # The property name.
+            &quot;value&quot;: &quot;A String&quot;, # The property value.
+          },
+        ],
+        &quot;unixMode&quot;: 42, # The UNIX file mode, e.g., 0755.
+      },
       &quot;path&quot;: &quot;A String&quot;, # The full path of the file relative to the working directory, including the filename. The path separator is a forward slash `/`. Since this is a relative path, it MUST NOT begin with a leading forward slash.
     },
   ],
   &quot;outputSymlinks&quot;: [ # New in v2.1: this field will only be populated if the command `output_paths` field was used, and not the pre v2.1 `output_files` or `output_directories` fields. The output paths of the action that are symbolic links to other paths. Those may be links to other outputs, or inputs, or even absolute paths outside of the working directory, if the server supports SymlinkAbsolutePathStrategy.ALLOWED. A single entry for each output requested in `output_paths` field of the Action, if the corresponding path existed after the action completed and was a symbolic link. If the action does not produce a requested output, then that output will be omitted from the list. The server is free to arrange the output list as desired; clients MUST NOT assume that the output list is sorted.
     { # An `OutputSymlink` is similar to a Symlink, but it is used as an output in an `ActionResult`. `OutputSymlink` is binary-compatible with `SymlinkNode`.
-      &quot;nodeProperties&quot;: [ # The supported node properties of the OutputSymlink, if requested by the Action.
-        { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
-          &quot;name&quot;: &quot;A String&quot;, # The property name.
-          &quot;value&quot;: &quot;A String&quot;, # The property value.
-        },
-      ],
+      &quot;nodeProperties&quot;: { # Node properties for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the properties that it accepts.
+        &quot;mtime&quot;: &quot;A String&quot;, # The file&#x27;s last modification timestamp.
+        &quot;properties&quot;: [ # A list of string-based NodeProperties.
+          { # A single property for FileNodes, DirectoryNodes, and SymlinkNodes. The server is responsible for specifying the property `name`s that it accepts. If permitted by the server, the same `name` may occur multiple times.
+            &quot;name&quot;: &quot;A String&quot;, # The property name.
+            &quot;value&quot;: &quot;A String&quot;, # The property value.
+          },
+        ],
+        &quot;unixMode&quot;: 42, # The UNIX file mode, e.g., 0755.
+      },
       &quot;path&quot;: &quot;A String&quot;, # The full path of the symlink relative to the working directory, including the filename. The path separator is a forward slash `/`. Since this is a relative path, it MUST NOT begin with a leading forward slash.
-      &quot;target&quot;: &quot;A String&quot;, # The target path of the symlink. The path separator is a forward slash `/`. The target path can be relative to the parent directory of the symlink or it can be an absolute path starting with `/`. Support for absolute paths can be checked using the Capabilities API. The canonical form forbids the substrings `/./` and `//` in the target path. `..` components are allowed anywhere in the target path.
+      &quot;target&quot;: &quot;A String&quot;, # The target path of the symlink. The path separator is a forward slash `/`. The target path can be relative to the parent directory of the symlink or it can be an absolute path starting with `/`. Support for absolute paths can be checked using the Capabilities API. `..` components are allowed anywhere in the target path.
     },
   ],
   &quot;stderrDigest&quot;: { # A content digest. A digest for a given blob consists of the size of the blob and its hash. The hash algorithm to use is defined by the server. The size is considered to be an integral part of the digest and cannot be separated. That is, even if the `hash` field is correctly specified but `size_bytes` is not, the server MUST reject the request. The reason for including the size in the digest is as follows: in a great many cases, the server needs to know the size of the blob it is about to work with prior to starting an operation with it, such as flattening Merkle tree structures or streaming it to a worker. Technically, the server could implement a separate metadata store, but this results in a significantly more complicated implementation as opposed to having the client specify the size up-front (or storing the size along with the digest in every message where digests are embedded). This does mean that the API leaks some implementation details of (what we consider to be) a reasonable server implementation, but we consider this to be a worthwhile tradeoff. When a `Digest` is used to refer to a proto message, it always refers to the message in binary encoded form. To ensure consistent hashing, clients and servers MUST ensure that they serialize messages according to the following rules, even if there are alternate valid encodings for the same message: * Fields are serialized in tag order. * There are no unknown fields. * There are no duplicate fields. * Fields are serialized according to the default semantics for their type. Most protocol buffer implementations will always follow these rules when serializing, but care should be taken to avoid shortcuts. For instance, concatenating two messages to merge them may produce duplicate fields. # The digest for a blob containing the standard error of the action, which can be retrieved from the ContentAddressableStorage.