Trains the specified agent.

        Operation <response: ``google.protobuf.Empty``,
        metadata: [google.protobuf.Struct][google.protobuf.Struct]>

        Example:
            >>> import dialogflow_v2
            >>>
            >>> client = dialogflow_v2.AgentsClient()
            >>>
            >>> parent = client.project_path('[PROJECT]')
            >>>
            >>> response = client.train_agent(parent)
            >>>
            >>> def callback(operation_future):
            ...     # Handle result.
            ...     result = operation_future.result()
            >>>
            >>> response.add_done_callback(callback)
            >>>
            >>> # Handle metadata.
            >>> metadata = response.metadata()

        Args:
            parent (str): Required. The project that the agent to train is associated with.
                Format: ``projects/<Project ID>``.
            retry (Optional[google.api_core.retry.Retry]):  A retry object used
                to retry requests. If ``None`` is specified, requests will not
                be retried.
            timeout (Optional[float]): The amount of time, in seconds, to wait
                for the request to complete. Note that if ``retry`` is
                specified, the timeout applies to each individual attempt.
            metadata (Optional[Sequence[Tuple[str, str]]]): Additional metadata
                that is provided to the method.

        Returns:
            A :class:`~google.cloud.dialogflow_v2.types._OperationFuture` instance.

        Raises:
            google.api_core.exceptions.GoogleAPICallError: If the request
                    failed for any reason.
            google.api_core.exceptions.RetryError: If the request failed due
                    to a retryable error and retry attempts failed.
            ValueError: If the parameters are invalid.

def train_agent(self,
                    parent,
                    retry=google.api_core.gapic_v1.method.DEFAULT,
                    timeout=google.api_core.gapic_v1.method.DEFAULT,
                    metadata=None):
        """
        Trains the specified agent.

        Operation <response: ``google.protobuf.Empty``,
        metadata: [google.protobuf.Struct][google.protobuf.Struct]>

        Example:
            >>> import dialogflow_v2
            >>>
            >>> client = dialogflow_v2.AgentsClient()
            >>>
            >>> parent = client.project_path('[PROJECT]')
            >>>
            >>> response = client.train_agent(parent)
            >>>
            >>> def callback(operation_future):
            ...     # Handle result.
            ...     result = operation_future.result()
            >>>
            >>> response.add_done_callback(callback)
            >>>
            >>> # Handle metadata.
            >>> metadata = response.metadata()

        Args:
            parent (str): Required. The project that the agent to train is associated with.
                Format: ``projects/<Project ID>``.
            retry (Optional[google.api_core.retry.Retry]):  A retry object used
                to retry requests. If ``None`` is specified, requests will not
                be retried.
            timeout (Optional[float]): The amount of time, in seconds, to wait
                for the request to complete. Note that if ``retry`` is
                specified, the timeout applies to each individual attempt.
            metadata (Optional[Sequence[Tuple[str, str]]]): Additional metadata
                that is provided to the method.

        Returns:
            A :class:`~google.cloud.dialogflow_v2.types._OperationFuture` instance.

        Raises:
            google.api_core.exceptions.GoogleAPICallError: If the request
                    failed for any reason.
            google.api_core.exceptions.RetryError: If the request failed due
                    to a retryable error and retry attempts failed.
            ValueError: If the parameters are invalid.
        """
        # Wrap the transport method to add retry and timeout logic.
        if 'train_agent' not in self._inner_api_calls:
            self._inner_api_calls[
                'train_agent'] = google.api_core.gapic_v1.method.wrap_method(
                    self.transport.train_agent,
                    default_retry=self._method_configs['TrainAgent'].retry,
                    default_timeout=self._method_configs['TrainAgent'].timeout,
                    client_info=self._client_info,
                )

        request = agent_pb2.TrainAgentRequest(parent=parent, )
        operation = self._inner_api_calls['train_agent'](
            request, retry=retry, timeout=timeout, metadata=metadata)
        return google.api_core.operation.from_gapic(
            operation,
            self.transport._operations_client,
            empty_pb2.Empty,
            metadata_type=struct_pb2.Struct,
        )