Regen all docs. (#700)

* Stop recursing if discovery == {}

* Generate docs with 'make docs'.
diff --git a/docs/dyn/bigquerydatatransfer_v1.projects.dataSources.html b/docs/dyn/bigquerydatatransfer_v1.projects.dataSources.html
index 8d11822..429a60c 100644
--- a/docs/dyn/bigquerydatatransfer_v1.projects.dataSources.html
+++ b/docs/dyn/bigquerydatatransfer_v1.projects.dataSources.html
@@ -72,10 +72,10 @@
 
 </style>
 
-<h1><a href="bigquerydatatransfer_v1.html">BigQuery Data Transfer Service API</a> . <a href="bigquerydatatransfer_v1.projects.html">projects</a> . <a href="bigquerydatatransfer_v1.projects.dataSources.html">dataSources</a></h1>
+<h1><a href="bigquerydatatransfer_v1.html">BigQuery Data Transfer API</a> . <a href="bigquerydatatransfer_v1.projects.html">projects</a> . <a href="bigquerydatatransfer_v1.projects.dataSources.html">dataSources</a></h1>
 <h2>Instance Methods</h2>
 <p class="toc_element">
-  <code><a href="#checkValidCreds">checkValidCreds(name, body, x__xgafv=None)</a></code></p>
+  <code><a href="#checkValidCreds">checkValidCreds(name, body=None, x__xgafv=None)</a></code></p>
 <p class="firstline">Returns true if valid credentials exist for the given data source and</p>
 <p class="toc_element">
   <code><a href="#get">get(name, x__xgafv=None)</a></code></p>
@@ -88,14 +88,18 @@
 <p class="firstline">Retrieves the next page of results.</p>
 <h3>Method Details</h3>
 <div class="method">
-    <code class="details" id="checkValidCreds">checkValidCreds(name, body, x__xgafv=None)</code>
+    <code class="details" id="checkValidCreds">checkValidCreds(name, body=None, x__xgafv=None)</code>
   <pre>Returns true if valid credentials exist for the given data source and
 requesting user.
+Some data sources doesn't support service account, so we need to talk to
+them on behalf of the end user. This API just checks whether we have OAuth
+token for the particular user, which is a pre-requisite before user can
+create a transfer config.
 
 Args:
   name: string, The data source in the form:
 `projects/{project_id}/dataSources/{data_source_id}` (required)
-  body: object, The request body. (required)
+  body: object, The request body.
     The object takes the form of:
 
 { # A request to determine whether the user has valid credentials. This method
@@ -137,25 +141,26 @@
 
     { # Represents data source metadata. Metadata is sufficient to
       # render UI and request proper OAuth tokens.
-    "scopes": [ # Api auth scopes for which refresh token needs to be obtained. Only valid
-        # when `client_id` is specified. Ignored otherwise. These are scopes needed
-        # by a data source to prepare data and ingest them into BigQuery,
-        # e.g., https://www.googleapis.com/auth/bigquery
+    "scopes": [ # Api auth scopes for which refresh token needs to be obtained. These are
+        # scopes needed by a data source to prepare data and ingest them into
+        # BigQuery, e.g., https://www.googleapis.com/auth/bigquery
       "A String",
     ],
-    "helpUrl": "A String", # Url for the help document for this data source.
-    "displayName": "A String", # User friendly data source name.
-    "name": "A String", # Data source resource name.
+    "minimumScheduleInterval": "A String", # The minimum interval for scheduler to schedule runs.
+    "supportsCustomSchedule": True or False, # Specifies whether the data source supports a user defined schedule, or
+        # operates on the default schedule.
+        # When set to `true`, user can override default schedule.
+    "name": "A String", # Output only. Data source resource name.
     "dataRefreshType": "A String", # Specifies whether the data source supports automatic data refresh for the
         # past few days, and how it's supported.
         # For some data sources, data might not be complete until a few days later,
         # so it's useful to refresh data automatically.
+    "helpUrl": "A String", # Url for the help document for this data source.
     "authorizationType": "A String", # Indicates the type of authorization.
     "description": "A String", # User friendly data source description string.
     "clientId": "A String", # Data source client id which should be used to receive refresh token.
-        # When not supplied, no offline credentials are populated for data transfer.
-    "statusUpdateDeadlineSeconds": 42, # The number of seconds to wait for a status update from the data source
-        # before BigQuery marks the transfer as failed.
+    "updateDeadlineSeconds": 42, # The number of seconds to wait for an update from the data source
+        # before the Data Transfer Service marks the transfer as FAILED.
     "manualRunsDisabled": True or False, # Disables backfilling and manual run scheduling
         # for the data source.
     "defaultSchedule": "A String", # Default data transfer schedule.
@@ -166,11 +171,8 @@
     "dataSourceId": "A String", # Data source id.
     "defaultDataRefreshWindowDays": 42, # Default data refresh window on days.
         # Only meaningful when `data_refresh_type` = `SLIDING_WINDOW`.
-    "supportsMultipleTransfers": True or False, # Indicates whether the data source supports multiple transfers
-        # to different BigQuery targets.
-    "supportsCustomSchedule": True or False, # Specifies whether the data source supports a user defined schedule, or
-        # operates on the default schedule.
-        # When set to `true`, user can override default schedule.
+    "supportsMultipleTransfers": True or False, # Deprecated. This field has no effect.
+    "displayName": "A String", # User friendly data source name.
     "parameters": [ # Data source parameters.
       { # Represents a data source parameter with validation rules, so that
           # parameters can be rendered in the UI. These parameters are given to us by
@@ -182,28 +184,25 @@
         "description": "A String", # Parameter description.
         "validationDescription": "A String", # Description of the requirements for this field, in case the user input does
             # not fulfill the regex pattern or min/max values.
-        "fields": [ # When parameter is a record, describes child fields.
+        "fields": [ # Deprecated. This field has no effect.
           # Object with schema name: DataSourceParameter
         ],
         "required": True or False, # Is parameter required.
-        "allowedValues": [ # All possible values for the parameter.
-          "A String",
-        ],
+        "recurse": True or False, # Deprecated. This field has no effect.
         "maxValue": 3.14, # For integer and double values specifies maxminum allowed value.
         "minValue": 3.14, # For integer and double values specifies minimum allowed value.
-        "repeated": True or False, # Can parameter have multiple values.
-        "recurse": True or False, # If set to true, schema should be taken from the parent with the same
-            # parameter_id. Only applicable when parameter type is RECORD.
+        "repeated": True or False, # Deprecated. This field has no effect.
         "validationRegex": "A String", # Regular expression which can be used for parameter validation.
         "validationHelpUrl": "A String", # URL to a help document to further explain the naming requirements.
         "paramId": "A String", # Parameter identifier.
         "type": "A String", # Parameter type.
         "immutable": True or False, # Cannot be changed after initial creation.
+        "allowedValues": [ # All possible values for the parameter.
+          "A String",
+        ],
       },
     ],
-    "transferType": "A String", # Transfer type. Currently supports only batch transfers,
-        # which are transfers that use the BigQuery batch APIs (load or
-        # query) to ingest the data.
+    "transferType": "A String", # Deprecated. This field has no effect.
   }</pre>
 </div>
 
@@ -230,33 +229,33 @@
   An object of the form:
 
     { # Returns list of supported data sources and their metadata.
-    "nextPageToken": "A String", # The next-pagination token. For multiple-page list results,
+    "nextPageToken": "A String", # Output only. The next-pagination token. For multiple-page list results,
         # this token can be used as the
         # `ListDataSourcesRequest.page_token`
         # to request the next page of list results.
-        # @OutputOnly
     "dataSources": [ # List of supported data sources and their transfer settings.
       { # Represents data source metadata. Metadata is sufficient to
           # render UI and request proper OAuth tokens.
-        "scopes": [ # Api auth scopes for which refresh token needs to be obtained. Only valid
-            # when `client_id` is specified. Ignored otherwise. These are scopes needed
-            # by a data source to prepare data and ingest them into BigQuery,
-            # e.g., https://www.googleapis.com/auth/bigquery
+        "scopes": [ # Api auth scopes for which refresh token needs to be obtained. These are
+            # scopes needed by a data source to prepare data and ingest them into
+            # BigQuery, e.g., https://www.googleapis.com/auth/bigquery
           "A String",
         ],
-        "helpUrl": "A String", # Url for the help document for this data source.
-        "displayName": "A String", # User friendly data source name.
-        "name": "A String", # Data source resource name.
+        "minimumScheduleInterval": "A String", # The minimum interval for scheduler to schedule runs.
+        "supportsCustomSchedule": True or False, # Specifies whether the data source supports a user defined schedule, or
+            # operates on the default schedule.
+            # When set to `true`, user can override default schedule.
+        "name": "A String", # Output only. Data source resource name.
         "dataRefreshType": "A String", # Specifies whether the data source supports automatic data refresh for the
             # past few days, and how it's supported.
             # For some data sources, data might not be complete until a few days later,
             # so it's useful to refresh data automatically.
+        "helpUrl": "A String", # Url for the help document for this data source.
         "authorizationType": "A String", # Indicates the type of authorization.
         "description": "A String", # User friendly data source description string.
         "clientId": "A String", # Data source client id which should be used to receive refresh token.
-            # When not supplied, no offline credentials are populated for data transfer.
-        "statusUpdateDeadlineSeconds": 42, # The number of seconds to wait for a status update from the data source
-            # before BigQuery marks the transfer as failed.
+        "updateDeadlineSeconds": 42, # The number of seconds to wait for an update from the data source
+            # before the Data Transfer Service marks the transfer as FAILED.
         "manualRunsDisabled": True or False, # Disables backfilling and manual run scheduling
             # for the data source.
         "defaultSchedule": "A String", # Default data transfer schedule.
@@ -267,11 +266,8 @@
         "dataSourceId": "A String", # Data source id.
         "defaultDataRefreshWindowDays": 42, # Default data refresh window on days.
             # Only meaningful when `data_refresh_type` = `SLIDING_WINDOW`.
-        "supportsMultipleTransfers": True or False, # Indicates whether the data source supports multiple transfers
-            # to different BigQuery targets.
-        "supportsCustomSchedule": True or False, # Specifies whether the data source supports a user defined schedule, or
-            # operates on the default schedule.
-            # When set to `true`, user can override default schedule.
+        "supportsMultipleTransfers": True or False, # Deprecated. This field has no effect.
+        "displayName": "A String", # User friendly data source name.
         "parameters": [ # Data source parameters.
           { # Represents a data source parameter with validation rules, so that
               # parameters can be rendered in the UI. These parameters are given to us by
@@ -283,28 +279,25 @@
             "description": "A String", # Parameter description.
             "validationDescription": "A String", # Description of the requirements for this field, in case the user input does
                 # not fulfill the regex pattern or min/max values.
-            "fields": [ # When parameter is a record, describes child fields.
+            "fields": [ # Deprecated. This field has no effect.
               # Object with schema name: DataSourceParameter
             ],
             "required": True or False, # Is parameter required.
-            "allowedValues": [ # All possible values for the parameter.
-              "A String",
-            ],
+            "recurse": True or False, # Deprecated. This field has no effect.
             "maxValue": 3.14, # For integer and double values specifies maxminum allowed value.
             "minValue": 3.14, # For integer and double values specifies minimum allowed value.
-            "repeated": True or False, # Can parameter have multiple values.
-            "recurse": True or False, # If set to true, schema should be taken from the parent with the same
-                # parameter_id. Only applicable when parameter type is RECORD.
+            "repeated": True or False, # Deprecated. This field has no effect.
             "validationRegex": "A String", # Regular expression which can be used for parameter validation.
             "validationHelpUrl": "A String", # URL to a help document to further explain the naming requirements.
             "paramId": "A String", # Parameter identifier.
             "type": "A String", # Parameter type.
             "immutable": True or False, # Cannot be changed after initial creation.
+            "allowedValues": [ # All possible values for the parameter.
+              "A String",
+            ],
           },
         ],
-        "transferType": "A String", # Transfer type. Currently supports only batch transfers,
-            # which are transfers that use the BigQuery batch APIs (load or
-            # query) to ingest the data.
+        "transferType": "A String", # Deprecated. This field has no effect.
       },
     ],
   }</pre>