'Test request_id column in messages is nullable.'

def _check_087(self, engine, data):

    self.assertTrue(engine.dialect.has_table(engine.connect(), 'messages'))
    messages = db_utils.get_table(engine, 'messages')
    self.assertIsInstance(messages.c.request_id.type, self.VARCHAR_TYPE)
    self.assertTrue(messages.c.request_id.nullable)
