<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def __write_docstring_return_type(self):
 """ Writes the return type part of the docstring for the wrapper method of a stored routine. """

        rtype = self._get_docstring_return_type()
        if rtype:
            self._write_line('')
            self._write_line(':rtype: {0}'.format(rtype))