docs: def _write_class_header(self):
          """
          Generate a class header for stored routine wrapper.
          """
          self._write_line('from {0!s} import {1!s}'.format(self._parent_class_namespace, self._parent_class_name))
          self._write_line()
          self._write_line()
          self._write_line('# ' + ('-' * 118))
          self._write_line('class {0!s}({1!s}):'.format(self._wrapper_class_name, self._parent_class_name))
          self._write_line('    """')
          self._write_line('    The stored routines wrappers.')
          self._write_line('    """')