code: def close(self):
          
          if self._closed:
              raise ProgrammingError('the connection is already closed')
          for cursor_ref in self._cursors:
              cursor = cursor_ref()
              if cursor is not None and not cursor._closed:
                  cursor.close()
          self._client.close_connection(self._id)
          self._client.close()
          self._closed = True
docs: Closes the connection.
          No further operations are allowed, either on the connection or any
          of its cursors, once the connection is closed.
  
          If the connection is used in a ``with`` statement, this method will
          be automatically called at the end of the ``with`` block.