code: def database(self, database_id, ddl_statements=(), pool=None):
          
          return Database(database_id, self, ddl_statements=ddl_statements, pool=pool)
docs: Factory to create a database within this instance.
  
          :type database_id: str
          :param database_id: The ID of the instance.
  
          :type ddl_statements: list of string
          :param ddl_statements: (Optional) DDL statements, excluding the
                                 'CREATE DATABSE' statement.
  
          :type pool: concrete subclass of
                      :class:`~google.cloud.spanner_v1.pool.AbstractSessionPool`.
          :param pool: (Optional) session pool to be used by database.
  
          :rtype: :class:`~google.cloud.spanner_v1.database.Database`
          :returns: a database owned by this instance.