chore: regens API reference docs (#889)

diff --git a/docs/dyn/cloudtrace_v2.projects.traces.spans.html b/docs/dyn/cloudtrace_v2.projects.traces.spans.html
index debd270..816c732 100644
--- a/docs/dyn/cloudtrace_v2.projects.traces.spans.html
+++ b/docs/dyn/cloudtrace_v2.projects.traces.spans.html
@@ -72,15 +72,17 @@
 
 </style>
 
-<h1><a href="cloudtrace_v2.html">Stackdriver Trace API</a> . <a href="cloudtrace_v2.projects.html">projects</a> . <a href="cloudtrace_v2.projects.traces.html">traces</a> . <a href="cloudtrace_v2.projects.traces.spans.html">spans</a></h1>
+<h1><a href="cloudtrace_v2.html">Cloud Trace API</a> . <a href="cloudtrace_v2.projects.html">projects</a> . <a href="cloudtrace_v2.projects.traces.html">traces</a> . <a href="cloudtrace_v2.projects.traces.spans.html">spans</a></h1>
 <h2>Instance Methods</h2>
 <p class="toc_element">
-  <code><a href="#createSpan">createSpan(name, body, x__xgafv=None)</a></code></p>
+  <code><a href="#createSpan">createSpan(name, body=None, x__xgafv=None)</a></code></p>
 <p class="firstline">Creates a new span.</p>
 <h3>Method Details</h3>
 <div class="method">
-    <code class="details" id="createSpan">createSpan(name, body, x__xgafv=None)</code>
+    <code class="details" id="createSpan">createSpan(name, body=None, x__xgafv=None)</code>
   <pre>Creates a new span.
+In this case, writing traces is not considered an active developer
+method since traces are machine generated.
 
 Args:
   name: string, The resource name of the span in the following format:
@@ -90,16 +92,16 @@
 
 [SPAN_ID] is a unique identifier for a span within a trace; it
 is a 16-character hexadecimal encoding of an 8-byte array. (required)
-  body: object, The request body. (required)
+  body: object, The request body.
     The object takes the form of:
 
 { # A span represents a single operation within a trace. Spans can be
     # nested to form a trace tree. Often, a trace contains a root span
     # that describes the end-to-end latency, and one or more subspans for
     # its sub-operations. A trace can also contain multiple root spans,
-    # or none at all. Spans do not need to be contiguous&mdash;there may be
+    # or none at all. Spans do not need to be contiguous&amp;mdash;there may be
     # gaps or overlaps between spans in a trace.
-  "status": { # The `Status` type defines a logical error model that is suitable for # An optional final status for this span.
+  "status": { # The `Status` type defines a logical error model that is suitable for # Optional. The final status for this span.
       # 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.
@@ -117,6 +119,76 @@
       },
     ],
   },
+  "childSpanCount": 42, # Optional. The number of child spans that were generated while this span
+      # was active. If set, allows implementation to detect missing child spans.
+  "displayName": { # Represents a string that might be shortened to a specified length. # Required. A description of the span's operation (up to 128 bytes).
+      # Stackdriver Trace displays the description in the
+      # Google Cloud Platform Console.
+      # For example, the display name can be a qualified method name or a file name
+      # and a line number where the operation is called. A best practice is to use
+      # the same display name within an application and at the same call point.
+      # This makes it easier to correlate spans in different traces.
+    "value": "A String", # The shortened string. For example, if the original string is 500
+        # bytes long and the limit of the string is 128 bytes, then
+        # `value` contains the first 128 bytes of the 500-byte string.
+        #
+        # Truncation always happens on a UTF8 character boundary. If there
+        # are multi-byte characters in the string, then the length of the
+        # shortened string might be less than the size limit.
+    "truncatedByteCount": 42, # The number of bytes removed from the original string. If this
+        # value is 0, then the string was not shortened.
+  },
+  "name": "A String", # The resource name of the span in the following format:
+      # 
+      #     projects/[PROJECT_ID]/traces/[TRACE_ID]/spans/SPAN_ID is a unique identifier for a trace within a project;
+      # it is a 32-character hexadecimal encoding of a 16-byte array.
+      # 
+      # [SPAN_ID] is a unique identifier for a span within a trace; it
+      # is a 16-character hexadecimal encoding of an 8-byte array.
+  "links": { # A collection of links, which are references from this span to a span # Links associated with the span. You can have up to 128 links per Span.
+      # in the same or different trace.
+    "droppedLinksCount": 42, # The number of dropped links after the maximum size was enforced. If
+        # this value is 0, then no links were dropped.
+    "link": [ # A collection of links.
+      { # A pointer from the current span to another span in the same trace or in a
+          # different trace. For example, this can be used in batching operations,
+          # where a single batch handler processes multiple requests from different
+          # traces or when the handler receives a request from a different project.
+        "attributes": { # A set of attributes, each in the format `[KEY]:[VALUE]`. # A set of attributes on the link. You have have up to  32 attributes per
+            # link.
+          "droppedAttributesCount": 42, # The number of attributes that were discarded. Attributes can be discarded
+              # because their keys are too long or because there are too many attributes.
+              # If this value is 0 then all attributes are valid.
+          "attributeMap": { # The set of attributes. Each attribute's key can be up to 128 bytes
+              # long. The value can be a string up to 256 bytes, a signed 64-bit integer,
+              # or the Boolean values `true` and `false`. For example:
+              #
+              #     "/instance_id": { "string_value": { "value": "my-instance" } }
+              #     "/http/request_bytes": { "int_value": 300 }
+              #     "abc.com/myattribute": { "bool_value": false }
+            "a_key": { # The allowed types for [VALUE] in a `[KEY]:[VALUE]` attribute.
+              "stringValue": { # Represents a string that might be shortened to a specified length. # A string up to 256 bytes long.
+                "value": "A String", # The shortened string. For example, if the original string is 500
+                    # bytes long and the limit of the string is 128 bytes, then
+                    # `value` contains the first 128 bytes of the 500-byte string.
+                    #
+                    # Truncation always happens on a UTF8 character boundary. If there
+                    # are multi-byte characters in the string, then the length of the
+                    # shortened string might be less than the size limit.
+                "truncatedByteCount": 42, # The number of bytes removed from the original string. If this
+                    # value is 0, then the string was not shortened.
+              },
+              "intValue": "A String", # A 64-bit signed integer.
+              "boolValue": True or False, # A Boolean value represented by `true` or `false`.
+            },
+          },
+        },
+        "traceId": "A String", # The [TRACE_ID] for a trace within a project.
+        "type": "A String", # The relationship of the current span relative to the linked span.
+        "spanId": "A String", # The [SPAN_ID] for a span within a trace.
+      },
+    ],
+  },
   "stackTrace": { # A call stack appearing in a trace. # Stack trace captured at the start of the span.
     "stackTraceHashId": "A String", # The hash ID is used to conserve network bandwidth for duplicate
         # stack traces within a single trace.
@@ -214,82 +286,15 @@
           # If this value is 0, then no stack frames were dropped.
     },
   },
-  "displayName": { # Represents a string that might be shortened to a specified length. # A description of the span's operation (up to 128 bytes).
-      # Stackdriver Trace displays the description in the
-      # Google Cloud Platform Console.
-      # For example, the display name can be a qualified method name or a file name
-      # and a line number where the operation is called. A best practice is to use
-      # the same display name within an application and at the same call point.
-      # This makes it easier to correlate spans in different traces.
-    "value": "A String", # The shortened string. For example, if the original string is 500
-        # bytes long and the limit of the string is 128 bytes, then
-        # `value` contains the first 128 bytes of the 500-byte string.
-        #
-        # Truncation always happens on a UTF8 character boundary. If there
-        # are multi-byte characters in the string, then the length of the
-        # shortened string might be less than the size limit.
-    "truncatedByteCount": 42, # The number of bytes removed from the original string. If this
-        # value is 0, then the string was not shortened.
-  },
-  "name": "A String", # The resource name of the span in the following format:
-      # 
-      #     projects/[PROJECT_ID]/traces/[TRACE_ID]/spans/SPAN_ID is a unique identifier for a trace within a project;
-      # it is a 32-character hexadecimal encoding of a 16-byte array.
-      # 
-      # [SPAN_ID] is a unique identifier for a span within a trace; it
-      # is a 16-character hexadecimal encoding of an 8-byte array.
-  "links": { # A collection of links, which are references from this span to a span # Links associated with the span. You can have up to 128 links per Span.
-      # in the same or different trace.
-    "droppedLinksCount": 42, # The number of dropped links after the maximum size was enforced. If
-        # this value is 0, then no links were dropped.
-    "link": [ # A collection of links.
-      { # A pointer from the current span to another span in the same trace or in a
-          # different trace. For example, this can be used in batching operations,
-          # where a single batch handler processes multiple requests from different
-          # traces or when the handler receives a request from a different project.
-        "attributes": { # A set of attributes, each in the format `[KEY]:[VALUE]`. # A set of attributes on the link. You have have up to  32 attributes per
-            # link.
-          "droppedAttributesCount": 42, # The number of attributes that were discarded. Attributes can be discarded
-              # because their keys are too long or because there are too many attributes.
-              # If this value is 0 then all attributes are valid.
-          "attributeMap": { # The set of attributes. Each attribute's key can be up to 128 bytes
-              # long. The value can be a string up to 256 bytes, a signed 64-bit integer,
-              # or the Boolean values `true` and `false`. For example:
-              #
-              #     "/instance_id": "my-instance"
-              #     "/http/user_agent": ""
-              #     "/http/request_bytes": 300
-              #     "abc.com/myattribute": true
-            "a_key": { # The allowed types for [VALUE] in a `[KEY]:[VALUE]` attribute.
-              "stringValue": { # Represents a string that might be shortened to a specified length. # A string up to 256 bytes long.
-                "value": "A String", # The shortened string. For example, if the original string is 500
-                    # bytes long and the limit of the string is 128 bytes, then
-                    # `value` contains the first 128 bytes of the 500-byte string.
-                    #
-                    # Truncation always happens on a UTF8 character boundary. If there
-                    # are multi-byte characters in the string, then the length of the
-                    # shortened string might be less than the size limit.
-                "truncatedByteCount": 42, # The number of bytes removed from the original string. If this
-                    # value is 0, then the string was not shortened.
-              },
-              "boolValue": True or False, # A Boolean value represented by `true` or `false`.
-              "intValue": "A String", # A 64-bit signed integer.
-            },
-          },
-        },
-        "traceId": "A String", # The [TRACE_ID] for a trace within a project.
-        "type": "A String", # The relationship of the current span relative to the linked span.
-        "spanId": "A String", # The [SPAN_ID] for a span within a trace.
-      },
-    ],
-  },
-  "childSpanCount": 42, # An optional number of child spans that were generated while this span
-      # was active. If set, allows implementation to detect missing child spans.
+  "spanKind": "A String", # Distinguishes between spans generated in a particular context. For example,
+      # two spans with the same name may be distinguished using `CLIENT` (caller)
+      # and `SERVER` (callee) to identify an RPC call.
   "parentSpanId": "A String", # The [SPAN_ID] of this span's parent span. If this is a root span,
       # then this field must be empty.
-  "startTime": "A String", # The start time of the span. On the client side, this is the time kept by
+  "startTime": "A String", # Required. The start time of the span. On the client side, this is the time kept by
       # the local machine where the span execution starts. On the server side, this
       # is the time when the server's application handler starts running.
+  "spanId": "A String", # Required. The [SPAN_ID] portion of the span's resource name.
   "attributes": { # A set of attributes, each in the format `[KEY]:[VALUE]`. # A set of attributes on the span. You can have up to 32 attributes per
       # span.
     "droppedAttributesCount": 42, # The number of attributes that were discarded. Attributes can be discarded
@@ -299,10 +304,9 @@
         # long. The value can be a string up to 256 bytes, a signed 64-bit integer,
         # or the Boolean values `true` and `false`. For example:
         #
-        #     "/instance_id": "my-instance"
-        #     "/http/user_agent": ""
-        #     "/http/request_bytes": 300
-        #     "abc.com/myattribute": true
+        #     "/instance_id": { "string_value": { "value": "my-instance" } }
+        #     "/http/request_bytes": { "int_value": 300 }
+        #     "abc.com/myattribute": { "bool_value": false }
       "a_key": { # The allowed types for [VALUE] in a `[KEY]:[VALUE]` attribute.
         "stringValue": { # Represents a string that might be shortened to a specified length. # A string up to 256 bytes long.
           "value": "A String", # The shortened string. For example, if the original string is 500
@@ -315,18 +319,15 @@
           "truncatedByteCount": 42, # The number of bytes removed from the original string. If this
               # value is 0, then the string was not shortened.
         },
-        "boolValue": True or False, # A Boolean value represented by `true` or `false`.
         "intValue": "A String", # A 64-bit signed integer.
+        "boolValue": True or False, # A Boolean value represented by `true` or `false`.
       },
     },
   },
-  "spanId": "A String", # The [SPAN_ID] portion of the span's resource name.
   "timeEvents": { # A collection of `TimeEvent`s. A `TimeEvent` is a time-stamped annotation # A set of time events. You can have up to 32 annotations and 128 message
       # events per span.
       # on the span, consisting of either user-supplied key:value pairs, or
       # details of a message sent/received between Spans.
-    "droppedMessageEventsCount": 42, # The number of dropped message events in all the included time events.
-        # If the value is 0, then no message events were dropped.
     "timeEvent": [ # A collection of `TimeEvent`s.
       { # A time-stamped annotation or message event in the Span.
         "messageEvent": { # An event describing a message sent/received between Spans. # An event describing a message sent/received between Spans.
@@ -349,10 +350,9 @@
                 # long. The value can be a string up to 256 bytes, a signed 64-bit integer,
                 # or the Boolean values `true` and `false`. For example:
                 #
-                #     "/instance_id": "my-instance"
-                #     "/http/user_agent": ""
-                #     "/http/request_bytes": 300
-                #     "abc.com/myattribute": true
+                #     "/instance_id": { "string_value": { "value": "my-instance" } }
+                #     "/http/request_bytes": { "int_value": 300 }
+                #     "abc.com/myattribute": { "bool_value": false }
               "a_key": { # The allowed types for [VALUE] in a `[KEY]:[VALUE]` attribute.
                 "stringValue": { # Represents a string that might be shortened to a specified length. # A string up to 256 bytes long.
                   "value": "A String", # The shortened string. For example, if the original string is 500
@@ -365,8 +365,8 @@
                   "truncatedByteCount": 42, # The number of bytes removed from the original string. If this
                       # value is 0, then the string was not shortened.
                 },
-                "boolValue": True or False, # A Boolean value represented by `true` or `false`.
                 "intValue": "A String", # A 64-bit signed integer.
+                "boolValue": True or False, # A Boolean value represented by `true` or `false`.
               },
             },
           },
@@ -386,13 +386,15 @@
         "time": "A String", # The timestamp indicating the time the event occurred.
       },
     ],
+    "droppedMessageEventsCount": 42, # The number of dropped message events in all the included time events.
+        # If the value is 0, then no message events were dropped.
     "droppedAnnotationsCount": 42, # The number of dropped annotations in all the included time events.
         # If the value is 0, then no annotations were dropped.
   },
-  "endTime": "A String", # The end time of the span. On the client side, this is the time kept by
+  "endTime": "A String", # Required. The end time of the span. On the client side, this is the time kept by
       # the local machine where the span execution ends. On the server side, this
       # is the time when the server application handler stops running.
-  "sameProcessAsParentSpan": True or False, # (Optional) Set this parameter to indicate whether this span is in
+  "sameProcessAsParentSpan": True or False, # Optional. Set this parameter to indicate whether this span is in
       # the same process as its parent. If you do not set this parameter,
       # Stackdriver Trace is unable to take advantage of this helpful
       # information.
@@ -410,9 +412,9 @@
       # nested to form a trace tree. Often, a trace contains a root span
       # that describes the end-to-end latency, and one or more subspans for
       # its sub-operations. A trace can also contain multiple root spans,
-      # or none at all. Spans do not need to be contiguous&mdash;there may be
+      # or none at all. Spans do not need to be contiguous&amp;mdash;there may be
       # gaps or overlaps between spans in a trace.
-    "status": { # The `Status` type defines a logical error model that is suitable for # An optional final status for this span.
+    "status": { # The `Status` type defines a logical error model that is suitable for # Optional. The final status for this span.
         # 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.
@@ -430,6 +432,76 @@
         },
       ],
     },
+    "childSpanCount": 42, # Optional. The number of child spans that were generated while this span
+        # was active. If set, allows implementation to detect missing child spans.
+    "displayName": { # Represents a string that might be shortened to a specified length. # Required. A description of the span's operation (up to 128 bytes).
+        # Stackdriver Trace displays the description in the
+        # Google Cloud Platform Console.
+        # For example, the display name can be a qualified method name or a file name
+        # and a line number where the operation is called. A best practice is to use
+        # the same display name within an application and at the same call point.
+        # This makes it easier to correlate spans in different traces.
+      "value": "A String", # The shortened string. For example, if the original string is 500
+          # bytes long and the limit of the string is 128 bytes, then
+          # `value` contains the first 128 bytes of the 500-byte string.
+          #
+          # Truncation always happens on a UTF8 character boundary. If there
+          # are multi-byte characters in the string, then the length of the
+          # shortened string might be less than the size limit.
+      "truncatedByteCount": 42, # The number of bytes removed from the original string. If this
+          # value is 0, then the string was not shortened.
+    },
+    "name": "A String", # The resource name of the span in the following format:
+        #
+        #     projects/[PROJECT_ID]/traces/[TRACE_ID]/spans/SPAN_ID is a unique identifier for a trace within a project;
+        # it is a 32-character hexadecimal encoding of a 16-byte array.
+        #
+        # [SPAN_ID] is a unique identifier for a span within a trace; it
+        # is a 16-character hexadecimal encoding of an 8-byte array.
+    "links": { # A collection of links, which are references from this span to a span # Links associated with the span. You can have up to 128 links per Span.
+        # in the same or different trace.
+      "droppedLinksCount": 42, # The number of dropped links after the maximum size was enforced. If
+          # this value is 0, then no links were dropped.
+      "link": [ # A collection of links.
+        { # A pointer from the current span to another span in the same trace or in a
+            # different trace. For example, this can be used in batching operations,
+            # where a single batch handler processes multiple requests from different
+            # traces or when the handler receives a request from a different project.
+          "attributes": { # A set of attributes, each in the format `[KEY]:[VALUE]`. # A set of attributes on the link. You have have up to  32 attributes per
+              # link.
+            "droppedAttributesCount": 42, # The number of attributes that were discarded. Attributes can be discarded
+                # because their keys are too long or because there are too many attributes.
+                # If this value is 0 then all attributes are valid.
+            "attributeMap": { # The set of attributes. Each attribute's key can be up to 128 bytes
+                # long. The value can be a string up to 256 bytes, a signed 64-bit integer,
+                # or the Boolean values `true` and `false`. For example:
+                #
+                #     "/instance_id": { "string_value": { "value": "my-instance" } }
+                #     "/http/request_bytes": { "int_value": 300 }
+                #     "abc.com/myattribute": { "bool_value": false }
+              "a_key": { # The allowed types for [VALUE] in a `[KEY]:[VALUE]` attribute.
+                "stringValue": { # Represents a string that might be shortened to a specified length. # A string up to 256 bytes long.
+                  "value": "A String", # The shortened string. For example, if the original string is 500
+                      # bytes long and the limit of the string is 128 bytes, then
+                      # `value` contains the first 128 bytes of the 500-byte string.
+                      #
+                      # Truncation always happens on a UTF8 character boundary. If there
+                      # are multi-byte characters in the string, then the length of the
+                      # shortened string might be less than the size limit.
+                  "truncatedByteCount": 42, # The number of bytes removed from the original string. If this
+                      # value is 0, then the string was not shortened.
+                },
+                "intValue": "A String", # A 64-bit signed integer.
+                "boolValue": True or False, # A Boolean value represented by `true` or `false`.
+              },
+            },
+          },
+          "traceId": "A String", # The [TRACE_ID] for a trace within a project.
+          "type": "A String", # The relationship of the current span relative to the linked span.
+          "spanId": "A String", # The [SPAN_ID] for a span within a trace.
+        },
+      ],
+    },
     "stackTrace": { # A call stack appearing in a trace. # Stack trace captured at the start of the span.
       "stackTraceHashId": "A String", # The hash ID is used to conserve network bandwidth for duplicate
           # stack traces within a single trace.
@@ -527,82 +599,15 @@
             # If this value is 0, then no stack frames were dropped.
       },
     },
-    "displayName": { # Represents a string that might be shortened to a specified length. # A description of the span's operation (up to 128 bytes).
-        # Stackdriver Trace displays the description in the
-        # Google Cloud Platform Console.
-        # For example, the display name can be a qualified method name or a file name
-        # and a line number where the operation is called. A best practice is to use
-        # the same display name within an application and at the same call point.
-        # This makes it easier to correlate spans in different traces.
-      "value": "A String", # The shortened string. For example, if the original string is 500
-          # bytes long and the limit of the string is 128 bytes, then
-          # `value` contains the first 128 bytes of the 500-byte string.
-          #
-          # Truncation always happens on a UTF8 character boundary. If there
-          # are multi-byte characters in the string, then the length of the
-          # shortened string might be less than the size limit.
-      "truncatedByteCount": 42, # The number of bytes removed from the original string. If this
-          # value is 0, then the string was not shortened.
-    },
-    "name": "A String", # The resource name of the span in the following format:
-        #
-        #     projects/[PROJECT_ID]/traces/[TRACE_ID]/spans/SPAN_ID is a unique identifier for a trace within a project;
-        # it is a 32-character hexadecimal encoding of a 16-byte array.
-        #
-        # [SPAN_ID] is a unique identifier for a span within a trace; it
-        # is a 16-character hexadecimal encoding of an 8-byte array.
-    "links": { # A collection of links, which are references from this span to a span # Links associated with the span. You can have up to 128 links per Span.
-        # in the same or different trace.
-      "droppedLinksCount": 42, # The number of dropped links after the maximum size was enforced. If
-          # this value is 0, then no links were dropped.
-      "link": [ # A collection of links.
-        { # A pointer from the current span to another span in the same trace or in a
-            # different trace. For example, this can be used in batching operations,
-            # where a single batch handler processes multiple requests from different
-            # traces or when the handler receives a request from a different project.
-          "attributes": { # A set of attributes, each in the format `[KEY]:[VALUE]`. # A set of attributes on the link. You have have up to  32 attributes per
-              # link.
-            "droppedAttributesCount": 42, # The number of attributes that were discarded. Attributes can be discarded
-                # because their keys are too long or because there are too many attributes.
-                # If this value is 0 then all attributes are valid.
-            "attributeMap": { # The set of attributes. Each attribute's key can be up to 128 bytes
-                # long. The value can be a string up to 256 bytes, a signed 64-bit integer,
-                # or the Boolean values `true` and `false`. For example:
-                #
-                #     "/instance_id": "my-instance"
-                #     "/http/user_agent": ""
-                #     "/http/request_bytes": 300
-                #     "abc.com/myattribute": true
-              "a_key": { # The allowed types for [VALUE] in a `[KEY]:[VALUE]` attribute.
-                "stringValue": { # Represents a string that might be shortened to a specified length. # A string up to 256 bytes long.
-                  "value": "A String", # The shortened string. For example, if the original string is 500
-                      # bytes long and the limit of the string is 128 bytes, then
-                      # `value` contains the first 128 bytes of the 500-byte string.
-                      #
-                      # Truncation always happens on a UTF8 character boundary. If there
-                      # are multi-byte characters in the string, then the length of the
-                      # shortened string might be less than the size limit.
-                  "truncatedByteCount": 42, # The number of bytes removed from the original string. If this
-                      # value is 0, then the string was not shortened.
-                },
-                "boolValue": True or False, # A Boolean value represented by `true` or `false`.
-                "intValue": "A String", # A 64-bit signed integer.
-              },
-            },
-          },
-          "traceId": "A String", # The [TRACE_ID] for a trace within a project.
-          "type": "A String", # The relationship of the current span relative to the linked span.
-          "spanId": "A String", # The [SPAN_ID] for a span within a trace.
-        },
-      ],
-    },
-    "childSpanCount": 42, # An optional number of child spans that were generated while this span
-        # was active. If set, allows implementation to detect missing child spans.
+    "spanKind": "A String", # Distinguishes between spans generated in a particular context. For example,
+        # two spans with the same name may be distinguished using `CLIENT` (caller)
+        # and `SERVER` (callee) to identify an RPC call.
     "parentSpanId": "A String", # The [SPAN_ID] of this span's parent span. If this is a root span,
         # then this field must be empty.
-    "startTime": "A String", # The start time of the span. On the client side, this is the time kept by
+    "startTime": "A String", # Required. The start time of the span. On the client side, this is the time kept by
         # the local machine where the span execution starts. On the server side, this
         # is the time when the server's application handler starts running.
+    "spanId": "A String", # Required. The [SPAN_ID] portion of the span's resource name.
     "attributes": { # A set of attributes, each in the format `[KEY]:[VALUE]`. # A set of attributes on the span. You can have up to 32 attributes per
         # span.
       "droppedAttributesCount": 42, # The number of attributes that were discarded. Attributes can be discarded
@@ -612,10 +617,9 @@
           # long. The value can be a string up to 256 bytes, a signed 64-bit integer,
           # or the Boolean values `true` and `false`. For example:
           #
-          #     "/instance_id": "my-instance"
-          #     "/http/user_agent": ""
-          #     "/http/request_bytes": 300
-          #     "abc.com/myattribute": true
+          #     "/instance_id": { "string_value": { "value": "my-instance" } }
+          #     "/http/request_bytes": { "int_value": 300 }
+          #     "abc.com/myattribute": { "bool_value": false }
         "a_key": { # The allowed types for [VALUE] in a `[KEY]:[VALUE]` attribute.
           "stringValue": { # Represents a string that might be shortened to a specified length. # A string up to 256 bytes long.
             "value": "A String", # The shortened string. For example, if the original string is 500
@@ -628,18 +632,15 @@
             "truncatedByteCount": 42, # The number of bytes removed from the original string. If this
                 # value is 0, then the string was not shortened.
           },
-          "boolValue": True or False, # A Boolean value represented by `true` or `false`.
           "intValue": "A String", # A 64-bit signed integer.
+          "boolValue": True or False, # A Boolean value represented by `true` or `false`.
         },
       },
     },
-    "spanId": "A String", # The [SPAN_ID] portion of the span's resource name.
     "timeEvents": { # A collection of `TimeEvent`s. A `TimeEvent` is a time-stamped annotation # A set of time events. You can have up to 32 annotations and 128 message
         # events per span.
         # on the span, consisting of either user-supplied key:value pairs, or
         # details of a message sent/received between Spans.
-      "droppedMessageEventsCount": 42, # The number of dropped message events in all the included time events.
-          # If the value is 0, then no message events were dropped.
       "timeEvent": [ # A collection of `TimeEvent`s.
         { # A time-stamped annotation or message event in the Span.
           "messageEvent": { # An event describing a message sent/received between Spans. # An event describing a message sent/received between Spans.
@@ -662,10 +663,9 @@
                   # long. The value can be a string up to 256 bytes, a signed 64-bit integer,
                   # or the Boolean values `true` and `false`. For example:
                   #
-                  #     "/instance_id": "my-instance"
-                  #     "/http/user_agent": ""
-                  #     "/http/request_bytes": 300
-                  #     "abc.com/myattribute": true
+                  #     "/instance_id": { "string_value": { "value": "my-instance" } }
+                  #     "/http/request_bytes": { "int_value": 300 }
+                  #     "abc.com/myattribute": { "bool_value": false }
                 "a_key": { # The allowed types for [VALUE] in a `[KEY]:[VALUE]` attribute.
                   "stringValue": { # Represents a string that might be shortened to a specified length. # A string up to 256 bytes long.
                     "value": "A String", # The shortened string. For example, if the original string is 500
@@ -678,8 +678,8 @@
                     "truncatedByteCount": 42, # The number of bytes removed from the original string. If this
                         # value is 0, then the string was not shortened.
                   },
-                  "boolValue": True or False, # A Boolean value represented by `true` or `false`.
                   "intValue": "A String", # A 64-bit signed integer.
+                  "boolValue": True or False, # A Boolean value represented by `true` or `false`.
                 },
               },
             },
@@ -699,13 +699,15 @@
           "time": "A String", # The timestamp indicating the time the event occurred.
         },
       ],
+      "droppedMessageEventsCount": 42, # The number of dropped message events in all the included time events.
+          # If the value is 0, then no message events were dropped.
       "droppedAnnotationsCount": 42, # The number of dropped annotations in all the included time events.
           # If the value is 0, then no annotations were dropped.
     },
-    "endTime": "A String", # The end time of the span. On the client side, this is the time kept by
+    "endTime": "A String", # Required. The end time of the span. On the client side, this is the time kept by
         # the local machine where the span execution ends. On the server side, this
         # is the time when the server application handler stops running.
-    "sameProcessAsParentSpan": True or False, # (Optional) Set this parameter to indicate whether this span is in
+    "sameProcessAsParentSpan": True or False, # Optional. Set this parameter to indicate whether this span is in
         # the same process as its parent. If you do not set this parameter,
         # Stackdriver Trace is unable to take advantage of this helpful
         # information.