<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def remove_from_tor(self, protocol):
        '''
        Returns a Deferred which fires with None
        '''
        r = yield protocol.queue_command('DEL_ONION %s' % self.hostname[:-6])
        if r.strip() != 'OK':
            raise RuntimeError('Failed to remove hidden service: "%s".' % r)