docs: docs update (#911)

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Fixes #<issue_number_goes_here> 🦕
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+
+<h1><a href="toolresults_v1beta3.html">Cloud Tool Results API</a> . <a href="toolresults_v1beta3.thumbnails.html">thumbnails</a></h1>
+<h2>Instance Methods</h2>
+<p class="toc_element">
+  <code><a href="#list">list(projectId, historyId, executionId, stepId, pageToken=None, pageSize=None, x__xgafv=None)</a></code></p>
+<p class="firstline">Lists thumbnails of images attached to a step.</p>
+<p class="toc_element">
+  <code><a href="#list_next">list_next(previous_request, previous_response)</a></code></p>
+<p class="firstline">Retrieves the next page of results.</p>
+<h3>Method Details</h3>
+<div class="method">
+    <code class="details" id="list">list(projectId, historyId, executionId, stepId, pageToken=None, pageSize=None, x__xgafv=None)</code>
+  <pre>Lists thumbnails of images attached to a step.
+
+May return any of the following canonical error codes:
+- PERMISSION_DENIED - if the user is not authorized to read from the
+                      project, or from any of the images
+- INVALID_ARGUMENT - if the request is malformed
+- NOT_FOUND - if the step does not exist, or if any of the images
+              do not exist
+
+Args:
+  projectId: string, A Project id.
+
+Required. (required)
+  historyId: string, A History id.
+
+Required. (required)
+  executionId: string, An Execution id.
+
+Required. (required)
+  stepId: string, A Step id.
+
+Required. (required)
+  pageToken: string, A continuation token to resume the query at the next item.
+
+Optional.
+  pageSize: integer, The maximum number of thumbnails to fetch.
+
+Default value: 50. The server will use this default if the field is not set
+or has a value of 0.
+
+Optional.
+  x__xgafv: string, V1 error format.
+    Allowed values
+      1 - v1 error format
+      2 - v2 error format
+
+Returns:
+  An object of the form:
+
+    { # A response containing the thumbnails in a step.
+    &quot;thumbnails&quot;: [ # A list of image data.
+        #
+        # Images are returned in a deterministic order; they are ordered by these
+        # factors, in order of
+        # importance:
+        # * First, by their associated test case. Images without a test case are
+        #   considered greater than images with one.
+        # * Second, by their creation time. Images without a creation time are
+        #   greater than images with one.
+        # * Third, by the order in which they were added to the step (by calls to
+        #   CreateStep or UpdateStep).
+      { # An image, with a link to the main image and a thumbnail.
+        &quot;sourceImage&quot;: { # A reference to a ToolExecution output file. # A reference to the full-size, original image.
+            #
+            # This is the same as the tool_outputs entry for the image under its Step.
+            #
+            # Always set.
+          &quot;creationTime&quot;: { # A Timestamp represents a point in time independent of any time zone or local # The creation time of the file.
+              #
+              # - In response: present if set by create/update request
+              # - In create/update request: optional
+              # calendar, encoded as a count of seconds and fractions of seconds at
+              # nanosecond resolution. The count is relative to an epoch at UTC midnight on
+              # January 1, 1970, in the proleptic Gregorian calendar which extends the
+              # Gregorian calendar backwards to year one.
+              #
+              # All minutes are 60 seconds long. Leap seconds are &quot;smeared&quot; so that no leap
+              # second table is needed for interpretation, using a [24-hour linear
+              # smear](https://developers.google.com/time/smear).
+              #
+              # The range is from 0001-01-01T00:00:00Z to 9999-12-31T23:59:59.999999999Z. By
+              # restricting to that range, we ensure that we can convert to and from [RFC
+              # 3339](https://www.ietf.org/rfc/rfc3339.txt) date strings.
+            &quot;nanos&quot;: 42, # Non-negative fractions of a second at nanosecond resolution. Negative
+                # second values with fractions must still have non-negative nanos values
+                # that count forward in time. Must be from 0 to 999,999,999
+                # inclusive.
+            &quot;seconds&quot;: &quot;A String&quot;, # Represents seconds of UTC time since Unix epoch
+                # 1970-01-01T00:00:00Z. Must be from 0001-01-01T00:00:00Z to
+                # 9999-12-31T23:59:59Z inclusive.
+          },
+          &quot;output&quot;: { # A reference to a file. # A FileReference to an output file.
+              #
+              # - In response: always set
+              # - In create/update request: always set
+            &quot;fileUri&quot;: &quot;A String&quot;, # The URI of a file stored in Google Cloud Storage.
+                #
+                # For example: http://storage.googleapis.com/mybucket/path/to/test.xml
+                # or in gsutil format: gs://mybucket/path/to/test.xml
+                # with version-specific info,
+                # gs://mybucket/path/to/test.xml#1360383693690000
+                #
+                # An INVALID_ARGUMENT error will be returned if the URI format is not
+                # supported.
+                #
+                # - In response: always set
+                # - In create/update request: always set
+          },
+          &quot;testCase&quot;: { # A reference to a test case. # The test case to which this output file belongs.
+              #
+              # - In response: present if set by create/update request
+              # - In create/update request: optional
+              #
+              # Test case references are canonically ordered lexicographically by these three
+              # factors:
+              # * First, by test_suite_name.
+              # * Second, by class_name.
+              # * Third, by name.
+            &quot;name&quot;: &quot;A String&quot;, # The name of the test case.
+                #
+                # Required.
+            &quot;testSuiteName&quot;: &quot;A String&quot;, # The name of the test suite to which this test case belongs.
+            &quot;className&quot;: &quot;A String&quot;, # The name of the class.
+          },
+        },
+        &quot;thumbnail&quot;: { # A single thumbnail, with its size and format. # The thumbnail.
+          &quot;data&quot;: &quot;A String&quot;, # The thumbnail file itself.
+              #
+              # That is, the bytes here are precisely the bytes that make up the thumbnail
+              # file; they can be served as an image as-is (with the appropriate content
+              # type.)
+              #
+              # Always set.
+          &quot;contentType&quot;: &quot;A String&quot;, # The thumbnail&#x27;s content type, i.e. &quot;image/png&quot;.
+              #
+              # Always set.
+          &quot;heightPx&quot;: 42, # The height of the thumbnail, in pixels.
+              #
+              # Always set.
+          &quot;widthPx&quot;: 42, # The width of the thumbnail, in pixels.
+              #
+              # Always set.
+        },
+        &quot;stepId&quot;: &quot;A String&quot;, # The step to which the image is attached.
+            #
+            # Always set.
+        &quot;error&quot;: { # The `Status` type defines a logical error model that is suitable for # An error explaining why the thumbnail could not be rendered.
+            # different programming environments, including REST APIs and RPC APIs. It is
+            # used by [gRPC](https://github.com/grpc). Each `Status` message contains
+            # three pieces of data: error code, error message, and error details.
+            #
+            # You can find out more about this error model and how to work with it in the
+            # [API Design Guide](https://cloud.google.com/apis/design/errors).
+          &quot;message&quot;: &quot;A String&quot;, # A developer-facing error message, which should be in English. Any
+              # user-facing error message should be localized and sent in the
+              # google.rpc.Status.details field, or localized by the client.
+          &quot;details&quot;: [ # A list of messages that carry the error details.  There is a common set of
+              # message types for APIs to use.
+            {
+              &quot;a_key&quot;: &quot;&quot;, # Properties of the object. Contains field @type with type URL.
+            },
+          ],
+          &quot;code&quot;: 42, # The status code, which should be an enum value of google.rpc.Code.
+        },
+      },
+    ],
+    &quot;nextPageToken&quot;: &quot;A String&quot;, # A continuation token to resume the query at the next item.
+        #
+        # If set, indicates that there are more thumbnails to read, by calling list
+        # again with this value in the page_token field.
+  }</pre>
+</div>
+
+<div class="method">
+    <code class="details" id="list_next">list_next(previous_request, previous_response)</code>
+  <pre>Retrieves the next page of results.
+
+Args:
+  previous_request: The request for the previous page. (required)
+  previous_response: The response from the request for the previous page. (required)
+
+Returns:
+  A request object that you can call &#x27;execute()&#x27; on to request the next
+  page. Returns None if there are no more items in the collection.
+    </pre>
+</div>
+
+</body></html>
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