Regen all docs. (#700)

* Stop recursing if discovery == {}

* Generate docs with 'make docs'.
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+
+<h1><a href="bigtableadmin_v2.html">Cloud Bigtable Admin API</a> . <a href="bigtableadmin_v2.projects.html">projects</a> . <a href="bigtableadmin_v2.projects.instances.html">instances</a> . <a href="bigtableadmin_v2.projects.instances.clusters.html">clusters</a></h1>
+<h2>Instance Methods</h2>
+<p class="toc_element">
+  <code><a href="#create">create(parent, body, clusterId=None, x__xgafv=None)</a></code></p>
+<p class="firstline">Creates a cluster within an instance.</p>
+<p class="toc_element">
+  <code><a href="#delete">delete(name, x__xgafv=None)</a></code></p>
+<p class="firstline">Deletes a cluster from an instance.</p>
+<p class="toc_element">
+  <code><a href="#get">get(name, x__xgafv=None)</a></code></p>
+<p class="firstline">Gets information about a cluster.</p>
+<p class="toc_element">
+  <code><a href="#list">list(parent, pageToken=None, x__xgafv=None)</a></code></p>
+<p class="firstline">Lists information about clusters in an instance.</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>
+<p class="toc_element">
+  <code><a href="#update">update(name, body, x__xgafv=None)</a></code></p>
+<p class="firstline">Updates a cluster within an instance.</p>
+<h3>Method Details</h3>
+<div class="method">
+    <code class="details" id="create">create(parent, body, clusterId=None, x__xgafv=None)</code>
+  <pre>Creates a cluster within an instance.
+
+Args:
+  parent: string, The unique name of the instance in which to create the new cluster.
+Values are of the form
+`projects/<project>/instances/<instance>`. (required)
+  body: object, The request body. (required)
+    The object takes the form of:
+
+{ # A resizable group of nodes in a particular cloud location, capable
+    # of serving all Tables in the parent
+    # Instance.
+  "defaultStorageType": "A String", # (`CreationOnly`)
+      # The type of storage used by this cluster to serve its
+      # parent instance's tables, unless explicitly overridden.
+  "serveNodes": 42, # The number of nodes allocated to this cluster. More nodes enable higher
+      # throughput and more consistent performance.
+  "state": "A String", # (`OutputOnly`)
+      # The current state of the cluster.
+  "location": "A String", # (`CreationOnly`)
+      # The location where this cluster's nodes and storage reside. For best
+      # performance, clients should be located as close as possible to this
+      # cluster. Currently only zones are supported, so values should be of the
+      # form `projects/<project>/locations/<zone>`.
+  "name": "A String", # (`OutputOnly`)
+      # The unique name of the cluster. Values are of the form
+      # `projects/<project>/instances/<instance>/clusters/a-z*`.
+}
+
+  clusterId: string, The ID to be used when referring to the new cluster within its instance,
+e.g., just `mycluster` rather than
+`projects/myproject/instances/myinstance/clusters/mycluster`.
+  x__xgafv: string, V1 error format.
+    Allowed values
+      1 - v1 error format
+      2 - v2 error format
+
+Returns:
+  An object of the form:
+
+    { # This resource represents a long-running operation that is the result of a
+      # network API call.
+    "metadata": { # Service-specific metadata associated with the operation.  It typically
+        # contains progress information and common metadata such as create time.
+        # Some services might not provide such metadata.  Any method that returns a
+        # long-running operation should document the metadata type, if any.
+      "a_key": "", # Properties of the object. Contains field @type with type URL.
+    },
+    "error": { # The `Status` type defines a logical error model that is suitable for # The error result of the operation in case of failure or cancellation.
+        # different programming environments, including REST APIs and RPC APIs. It is
+        # used by [gRPC](https://github.com/grpc). The error model is designed to be:
+        #
+        # - Simple to use and understand for most users
+        # - Flexible enough to meet unexpected needs
+        #
+        # # Overview
+        #
+        # The `Status` message contains three pieces of data: error code, error
+        # message, and error details. The error code should be an enum value of
+        # google.rpc.Code, but it may accept additional error codes if needed.  The
+        # error message should be a developer-facing English message that helps
+        # developers *understand* and *resolve* the error. If a localized user-facing
+        # error message is needed, put the localized message in the error details or
+        # localize it in the client. The optional error details may contain arbitrary
+        # information about the error. There is a predefined set of error detail types
+        # in the package `google.rpc` that can be used for common error conditions.
+        #
+        # # Language mapping
+        #
+        # The `Status` message is the logical representation of the error model, but it
+        # is not necessarily the actual wire format. When the `Status` message is
+        # exposed in different client libraries and different wire protocols, it can be
+        # mapped differently. For example, it will likely be mapped to some exceptions
+        # in Java, but more likely mapped to some error codes in C.
+        #
+        # # Other uses
+        #
+        # The error model and the `Status` message can be used in a variety of
+        # environments, either with or without APIs, to provide a
+        # consistent developer experience across different environments.
+        #
+        # Example uses of this error model include:
+        #
+        # - Partial errors. If a service needs to return partial errors to the client,
+        #     it may embed the `Status` in the normal response to indicate the partial
+        #     errors.
+        #
+        # - Workflow errors. A typical workflow has multiple steps. Each step may
+        #     have a `Status` message for error reporting.
+        #
+        # - Batch operations. If a client uses batch request and batch response, the
+        #     `Status` message should be used directly inside batch response, one for
+        #     each error sub-response.
+        #
+        # - Asynchronous operations. If an API call embeds asynchronous operation
+        #     results in its response, the status of those operations should be
+        #     represented directly using the `Status` message.
+        #
+        # - Logging. If some API errors are stored in logs, the message `Status` could
+        #     be used directly after any stripping needed for security/privacy reasons.
+      "message": "A String", # 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.
+      "code": 42, # The status code, which should be an enum value of google.rpc.Code.
+      "details": [ # A list of messages that carry the error details.  There is a common set of
+          # message types for APIs to use.
+        {
+          "a_key": "", # Properties of the object. Contains field @type with type URL.
+        },
+      ],
+    },
+    "done": True or False, # If the value is `false`, it means the operation is still in progress.
+        # If `true`, the operation is completed, and either `error` or `response` is
+        # available.
+    "response": { # The normal response of the operation in case of success.  If the original
+        # method returns no data on success, such as `Delete`, the response is
+        # `google.protobuf.Empty`.  If the original method is standard
+        # `Get`/`Create`/`Update`, the response should be the resource.  For other
+        # methods, the response should have the type `XxxResponse`, where `Xxx`
+        # is the original method name.  For example, if the original method name
+        # is `TakeSnapshot()`, the inferred response type is
+        # `TakeSnapshotResponse`.
+      "a_key": "", # Properties of the object. Contains field @type with type URL.
+    },
+    "name": "A String", # The server-assigned name, which is only unique within the same service that
+        # originally returns it. If you use the default HTTP mapping, the
+        # `name` should have the format of `operations/some/unique/name`.
+  }</pre>
+</div>
+
+<div class="method">
+    <code class="details" id="delete">delete(name, x__xgafv=None)</code>
+  <pre>Deletes a cluster from an instance.
+
+Args:
+  name: string, The unique name of the cluster to be deleted. Values are of the form
+`projects/<project>/instances/<instance>/clusters/<cluster>`. (required)
+  x__xgafv: string, V1 error format.
+    Allowed values
+      1 - v1 error format
+      2 - v2 error format
+
+Returns:
+  An object of the form:
+
+    { # A generic empty message that you can re-use to avoid defining duplicated
+      # empty messages in your APIs. A typical example is to use it as the request
+      # or the response type of an API method. For instance:
+      #
+      #     service Foo {
+      #       rpc Bar(google.protobuf.Empty) returns (google.protobuf.Empty);
+      #     }
+      #
+      # The JSON representation for `Empty` is empty JSON object `{}`.
+  }</pre>
+</div>
+
+<div class="method">
+    <code class="details" id="get">get(name, x__xgafv=None)</code>
+  <pre>Gets information about a cluster.
+
+Args:
+  name: string, The unique name of the requested cluster. Values are of the form
+`projects/<project>/instances/<instance>/clusters/<cluster>`. (required)
+  x__xgafv: string, V1 error format.
+    Allowed values
+      1 - v1 error format
+      2 - v2 error format
+
+Returns:
+  An object of the form:
+
+    { # A resizable group of nodes in a particular cloud location, capable
+      # of serving all Tables in the parent
+      # Instance.
+    "defaultStorageType": "A String", # (`CreationOnly`)
+        # The type of storage used by this cluster to serve its
+        # parent instance's tables, unless explicitly overridden.
+    "serveNodes": 42, # The number of nodes allocated to this cluster. More nodes enable higher
+        # throughput and more consistent performance.
+    "state": "A String", # (`OutputOnly`)
+        # The current state of the cluster.
+    "location": "A String", # (`CreationOnly`)
+        # The location where this cluster's nodes and storage reside. For best
+        # performance, clients should be located as close as possible to this
+        # cluster. Currently only zones are supported, so values should be of the
+        # form `projects/<project>/locations/<zone>`.
+    "name": "A String", # (`OutputOnly`)
+        # The unique name of the cluster. Values are of the form
+        # `projects/<project>/instances/<instance>/clusters/a-z*`.
+  }</pre>
+</div>
+
+<div class="method">
+    <code class="details" id="list">list(parent, pageToken=None, x__xgafv=None)</code>
+  <pre>Lists information about clusters in an instance.
+
+Args:
+  parent: string, The unique name of the instance for which a list of clusters is requested.
+Values are of the form `projects/<project>/instances/<instance>`.
+Use `<instance> = '-'` to list Clusters for all Instances in a project,
+e.g., `projects/myproject/instances/-`. (required)
+  pageToken: string, DEPRECATED: This field is unused and ignored.
+  x__xgafv: string, V1 error format.
+    Allowed values
+      1 - v1 error format
+      2 - v2 error format
+
+Returns:
+  An object of the form:
+
+    { # Response message for BigtableInstanceAdmin.ListClusters.
+    "nextPageToken": "A String", # DEPRECATED: This field is unused and ignored.
+    "clusters": [ # The list of requested clusters.
+      { # A resizable group of nodes in a particular cloud location, capable
+          # of serving all Tables in the parent
+          # Instance.
+        "defaultStorageType": "A String", # (`CreationOnly`)
+            # The type of storage used by this cluster to serve its
+            # parent instance's tables, unless explicitly overridden.
+        "serveNodes": 42, # The number of nodes allocated to this cluster. More nodes enable higher
+            # throughput and more consistent performance.
+        "state": "A String", # (`OutputOnly`)
+            # The current state of the cluster.
+        "location": "A String", # (`CreationOnly`)
+            # The location where this cluster's nodes and storage reside. For best
+            # performance, clients should be located as close as possible to this
+            # cluster. Currently only zones are supported, so values should be of the
+            # form `projects/<project>/locations/<zone>`.
+        "name": "A String", # (`OutputOnly`)
+            # The unique name of the cluster. Values are of the form
+            # `projects/<project>/instances/<instance>/clusters/a-z*`.
+      },
+    ],
+    "failedLocations": [ # Locations from which Cluster information could not be retrieved,
+        # due to an outage or some other transient condition.
+        # Clusters from these locations may be missing from `clusters`,
+        # or may only have partial information returned.
+        # Values are of the form `projects/<project>/locations/<zone_id>`
+      "A String",
+    ],
+  }</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 'execute()' on to request the next
+  page. Returns None if there are no more items in the collection.
+    </pre>
+</div>
+
+<div class="method">
+    <code class="details" id="update">update(name, body, x__xgafv=None)</code>
+  <pre>Updates a cluster within an instance.
+
+Args:
+  name: string, (`OutputOnly`)
+The unique name of the cluster. Values are of the form
+`projects/<project>/instances/<instance>/clusters/a-z*`. (required)
+  body: object, The request body. (required)
+    The object takes the form of:
+
+{ # A resizable group of nodes in a particular cloud location, capable
+    # of serving all Tables in the parent
+    # Instance.
+  "defaultStorageType": "A String", # (`CreationOnly`)
+      # The type of storage used by this cluster to serve its
+      # parent instance's tables, unless explicitly overridden.
+  "serveNodes": 42, # The number of nodes allocated to this cluster. More nodes enable higher
+      # throughput and more consistent performance.
+  "state": "A String", # (`OutputOnly`)
+      # The current state of the cluster.
+  "location": "A String", # (`CreationOnly`)
+      # The location where this cluster's nodes and storage reside. For best
+      # performance, clients should be located as close as possible to this
+      # cluster. Currently only zones are supported, so values should be of the
+      # form `projects/<project>/locations/<zone>`.
+  "name": "A String", # (`OutputOnly`)
+      # The unique name of the cluster. Values are of the form
+      # `projects/<project>/instances/<instance>/clusters/a-z*`.
+}
+
+  x__xgafv: string, V1 error format.
+    Allowed values
+      1 - v1 error format
+      2 - v2 error format
+
+Returns:
+  An object of the form:
+
+    { # This resource represents a long-running operation that is the result of a
+      # network API call.
+    "metadata": { # Service-specific metadata associated with the operation.  It typically
+        # contains progress information and common metadata such as create time.
+        # Some services might not provide such metadata.  Any method that returns a
+        # long-running operation should document the metadata type, if any.
+      "a_key": "", # Properties of the object. Contains field @type with type URL.
+    },
+    "error": { # The `Status` type defines a logical error model that is suitable for # The error result of the operation in case of failure or cancellation.
+        # different programming environments, including REST APIs and RPC APIs. It is
+        # used by [gRPC](https://github.com/grpc). The error model is designed to be:
+        #
+        # - Simple to use and understand for most users
+        # - Flexible enough to meet unexpected needs
+        #
+        # # Overview
+        #
+        # The `Status` message contains three pieces of data: error code, error
+        # message, and error details. The error code should be an enum value of
+        # google.rpc.Code, but it may accept additional error codes if needed.  The
+        # error message should be a developer-facing English message that helps
+        # developers *understand* and *resolve* the error. If a localized user-facing
+        # error message is needed, put the localized message in the error details or
+        # localize it in the client. The optional error details may contain arbitrary
+        # information about the error. There is a predefined set of error detail types
+        # in the package `google.rpc` that can be used for common error conditions.
+        #
+        # # Language mapping
+        #
+        # The `Status` message is the logical representation of the error model, but it
+        # is not necessarily the actual wire format. When the `Status` message is
+        # exposed in different client libraries and different wire protocols, it can be
+        # mapped differently. For example, it will likely be mapped to some exceptions
+        # in Java, but more likely mapped to some error codes in C.
+        #
+        # # Other uses
+        #
+        # The error model and the `Status` message can be used in a variety of
+        # environments, either with or without APIs, to provide a
+        # consistent developer experience across different environments.
+        #
+        # Example uses of this error model include:
+        #
+        # - Partial errors. If a service needs to return partial errors to the client,
+        #     it may embed the `Status` in the normal response to indicate the partial
+        #     errors.
+        #
+        # - Workflow errors. A typical workflow has multiple steps. Each step may
+        #     have a `Status` message for error reporting.
+        #
+        # - Batch operations. If a client uses batch request and batch response, the
+        #     `Status` message should be used directly inside batch response, one for
+        #     each error sub-response.
+        #
+        # - Asynchronous operations. If an API call embeds asynchronous operation
+        #     results in its response, the status of those operations should be
+        #     represented directly using the `Status` message.
+        #
+        # - Logging. If some API errors are stored in logs, the message `Status` could
+        #     be used directly after any stripping needed for security/privacy reasons.
+      "message": "A String", # 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.
+      "code": 42, # The status code, which should be an enum value of google.rpc.Code.
+      "details": [ # A list of messages that carry the error details.  There is a common set of
+          # message types for APIs to use.
+        {
+          "a_key": "", # Properties of the object. Contains field @type with type URL.
+        },
+      ],
+    },
+    "done": True or False, # If the value is `false`, it means the operation is still in progress.
+        # If `true`, the operation is completed, and either `error` or `response` is
+        # available.
+    "response": { # The normal response of the operation in case of success.  If the original
+        # method returns no data on success, such as `Delete`, the response is
+        # `google.protobuf.Empty`.  If the original method is standard
+        # `Get`/`Create`/`Update`, the response should be the resource.  For other
+        # methods, the response should have the type `XxxResponse`, where `Xxx`
+        # is the original method name.  For example, if the original method name
+        # is `TakeSnapshot()`, the inferred response type is
+        # `TakeSnapshotResponse`.
+      "a_key": "", # Properties of the object. Contains field @type with type URL.
+    },
+    "name": "A String", # The server-assigned name, which is only unique within the same service that
+        # originally returns it. If you use the default HTTP mapping, the
+        # `name` should have the format of `operations/some/unique/name`.
+  }</pre>
+</div>
+
+</body></html>
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