Fix method doc signatures for multiline required parameters (#374)

* Fix method doc signatures for multiline required parameters.

Existing doc generator failed to recognize parameters as required when parameter descriptions
extended over more than one line. Besides presenting incorrect information, resulting
inconsistencies broke checks for automated sample generation.

* Regen docs
diff --git a/docs/dyn/tracing_v1.projects.traces.html b/docs/dyn/tracing_v1.projects.traces.html
index c73bd7e..f4d3c0e 100644
--- a/docs/dyn/tracing_v1.projects.traces.html
+++ b/docs/dyn/tracing_v1.projects.traces.html
@@ -84,7 +84,7 @@
   <code><a href="#list">list(parent, orderBy=None, startTime=None, pageSize=None, x__xgafv=None, pageToken=None, filter=None, endTime=None)</a></code></p>
 <p class="firstline">Returns of a list of traces that match the specified filter conditions.</p>
 <p class="toc_element">
-  <code><a href="#listSpans">listSpans(name=None, pageToken=None, x__xgafv=None)</a></code></p>
+  <code><a href="#listSpans">listSpans(name, pageToken=None, x__xgafv=None)</a></code></p>
 <p class="firstline">Returns a list of spans within a trace.</p>
 <p class="toc_element">
   <code><a href="#listSpans_next">listSpans_next(previous_request, previous_response)</a></code></p>
@@ -196,7 +196,9 @@
                   "functionName": "A String", # The fully-qualified name that uniquely identifies this function or
                       # method.
                   "fileName": "A String", # The filename of the file containing this frame.
-                  "sourceVersion": "A String", # The version of the deployed source code.
+                  "originalFunctionName": "A String", # Used when the function name is
+                      # [mangled](http://www.avabodh.com/cxxin/namemangling.html). May be
+                      # fully-qualified.
                   "loadModule": { # Binary module. # Binary module the code is loaded from.
                     "buildId": "A String", # Build_id is a unique identifier for the module,
                         # usually a hash of its contents
@@ -204,9 +206,7 @@
                         # such as libc.so, sharedlib.so
                   },
                   "lineNumber": "A String", # Line number of the frame.
-                  "originalFunctionName": "A String", # Used when the function name is
-                      # [mangled](http://www.avabodh.com/cxxin/namemangling.html). May be
-                      # fully-qualified.
+                  "sourceVersion": "A String", # The version of the deployed source code.
                 },
               ],
             },
@@ -226,13 +226,13 @@
                 "type": "A String", # The relationship of the current span relative to the linked span.
               },
             ],
-            "parentId": "A String", # ID of the parent span. If this is a root span, the value must be `0` or
-                # empty.
             "localEndTime": "A String", # End time of the span.
                 # On the client side, this is the local machine clock time at which the span
                 # execution was ended; on the server
                 # side, this is the time at which the server application handler stopped
                 # running.
+            "parentId": "A String", # ID of the parent span. If this is a root span, the value must be `0` or
+                # empty.
             "attributes": { # Properties of a span in key:value format. The maximum length for the
                 # key is 128 characters. The value can be a string (up to 2000 characters),
                 # int, or boolean.
@@ -396,7 +396,7 @@
 </div>
 
 <div class="method">
-    <code class="details" id="listSpans">listSpans(name=None, pageToken=None, x__xgafv=None)</code>
+    <code class="details" id="listSpans">listSpans(name, pageToken=None, x__xgafv=None)</code>
   <pre>Returns a list of spans within a trace.
 
 Args:
@@ -503,7 +503,9 @@
               "functionName": "A String", # The fully-qualified name that uniquely identifies this function or
                   # method.
               "fileName": "A String", # The filename of the file containing this frame.
-              "sourceVersion": "A String", # The version of the deployed source code.
+              "originalFunctionName": "A String", # Used when the function name is
+                  # [mangled](http://www.avabodh.com/cxxin/namemangling.html). May be
+                  # fully-qualified.
               "loadModule": { # Binary module. # Binary module the code is loaded from.
                 "buildId": "A String", # Build_id is a unique identifier for the module,
                     # usually a hash of its contents
@@ -511,9 +513,7 @@
                     # such as libc.so, sharedlib.so
               },
               "lineNumber": "A String", # Line number of the frame.
-              "originalFunctionName": "A String", # Used when the function name is
-                  # [mangled](http://www.avabodh.com/cxxin/namemangling.html). May be
-                  # fully-qualified.
+              "sourceVersion": "A String", # The version of the deployed source code.
             },
           ],
         },
@@ -533,13 +533,13 @@
             "type": "A String", # The relationship of the current span relative to the linked span.
           },
         ],
-        "parentId": "A String", # ID of the parent span. If this is a root span, the value must be `0` or
-            # empty.
         "localEndTime": "A String", # End time of the span.
             # On the client side, this is the local machine clock time at which the span
             # execution was ended; on the server
             # side, this is the time at which the server application handler stopped
             # running.
+        "parentId": "A String", # ID of the parent span. If this is a root span, the value must be `0` or
+            # empty.
         "attributes": { # Properties of a span in key:value format. The maximum length for the
             # key is 128 characters. The value can be a string (up to 2000 characters),
             # int, or boolean.