Creates a new Cloud Spanner database and starts to prepare it for
        serving. The returned ``long-running operation`` will have a name of the
        format ``<database_name>/operations/<operation_id>`` and can be used to
        track preparation of the database. The ``metadata`` field type is
        ``CreateDatabaseMetadata``. The ``response`` field type is ``Database``,
        if successful.

        Example:
            >>> from google.cloud import spanner_admin_database_v1
            >>>
            >>> client = spanner_admin_database_v1.DatabaseAdminClient()
            >>>
            >>> parent = client.instance_path('[PROJECT]', '[INSTANCE]')
            >>>
            >>> # TODO: Initialize `create_statement`:
            >>> create_statement = ''
            >>>
            >>> response = client.create_database(parent, create_statement)
            >>>
            >>> 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 name of the instance that will serve the new database.
                Values are of the form ``projects/<project>/instances/<instance>``.
            create_statement (str): Required. A ``CREATE DATABASE`` statement, which specifies the ID of the
                new database. The database ID must conform to the regular expression
                ``[a-z][a-z0-9_\-]*[a-z0-9]`` and be between 2 and 30 characters in
                length. If the database ID is a reserved word or if it contains a
                hyphen, the database ID must be enclosed in backticks (`````).
            extra_statements (list[str]): An optional list of DDL statements to run inside the newly created
                database. Statements can create tables, indexes, etc. These
                statements execute atomically with the creation of the database:
                if there is an error in any statement, the database is not created.
            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.spanner_admin_database_v1.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 create_database(
        self,
        parent,
        create_statement,
        extra_statements=None,
        retry=google.api_core.gapic_v1.method.DEFAULT,
        timeout=google.api_core.gapic_v1.method.DEFAULT,
        metadata=None,
    ):
        """
        Creates a new Cloud Spanner database and starts to prepare it for
        serving. The returned ``long-running operation`` will have a name of the
        format ``<database_name>/operations/<operation_id>`` and can be used to
        track preparation of the database. The ``metadata`` field type is
        ``CreateDatabaseMetadata``. The ``response`` field type is ``Database``,
        if successful.

        Example:
            >>> from google.cloud import spanner_admin_database_v1
            >>>
            >>> client = spanner_admin_database_v1.DatabaseAdminClient()
            >>>
            >>> parent = client.instance_path('[PROJECT]', '[INSTANCE]')
            >>>
            >>> # TODO: Initialize `create_statement`:
            >>> create_statement = ''
            >>>
            >>> response = client.create_database(parent, create_statement)
            >>>
            >>> 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 name of the instance that will serve the new database.
                Values are of the form ``projects/<project>/instances/<instance>``.
            create_statement (str): Required. A ``CREATE DATABASE`` statement, which specifies the ID of the
                new database. The database ID must conform to the regular expression
                ``[a-z][a-z0-9_\-]*[a-z0-9]`` and be between 2 and 30 characters in
                length. If the database ID is a reserved word or if it contains a
                hyphen, the database ID must be enclosed in backticks (`````).
            extra_statements (list[str]): An optional list of DDL statements to run inside the newly created
                database. Statements can create tables, indexes, etc. These
                statements execute atomically with the creation of the database:
                if there is an error in any statement, the database is not created.
            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.spanner_admin_database_v1.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 "create_database" not in self._inner_api_calls:
            self._inner_api_calls[
                "create_database"
            ] = google.api_core.gapic_v1.method.wrap_method(
                self.transport.create_database,
                default_retry=self._method_configs["CreateDatabase"].retry,
                default_timeout=self._method_configs["CreateDatabase"].timeout,
                client_info=self._client_info,
            )

        request = spanner_database_admin_pb2.CreateDatabaseRequest(
            parent=parent,
            create_statement=create_statement,
            extra_statements=extra_statements,
        )
        if metadata is None:
            metadata = []
        metadata = list(metadata)
        try:
            routing_header = [("parent", parent)]
        except AttributeError:
            pass
        else:
            routing_metadata = google.api_core.gapic_v1.routing_header.to_grpc_metadata(
                routing_header
            )
            metadata.append(routing_metadata)

        operation = self._inner_api_calls["create_database"](
            request, retry=retry, timeout=timeout, metadata=metadata
        )
        return google.api_core.operation.from_gapic(
            operation,
            self.transport._operations_client,
            spanner_database_admin_pb2.Database,
            metadata_type=spanner_database_admin_pb2.CreateDatabaseMetadata,
        )