'Creating the same reaction twice fails'

def test_add_existing_reaction(self):

    pm_sender = self.example_email('hamlet')
    pm_recipient = self.example_email('othello')
    reaction_sender = pm_recipient
    pm = self.client_post('/api/v1/messages', {'type': 'private', 'content': 'Test    message', 'to': pm_recipient}, **self.api_auth(pm_sender))
    self.assert_json_success(pm)
    content = ujson.loads(pm.content)
    pm_id = content['id']
    first = self.client_put(('/api/v1/messages/%s/emoji_reactions/smile' % (pm_id,)), **self.api_auth(reaction_sender))
    self.assert_json_success(first)
    second = self.client_put(('/api/v1/messages/%s/emoji_reactions/smile' % (pm_id,)), **self.api_auth(reaction_sender))
    self.assert_json_error(second, 'Reaction    already    exists')
