human
Solve the following python programming problem given the following code:
@ pytest.fixture 
def mock_draft_sent_response() : 
    body = { 
        'bcc' : [], 
        'body' : '', 
        'cc' : [], 
        'date' : 1438684486, 
        'events' : [], 
        'files' : [], 
        'folder' : None, 
        'from' : [{ 
            'email' : 'benb@nylas.com', 
}], 
        'id' : '2h111aefv8pzwzfykrn7hercj', 
        'namespace_id' : '384uhp3aj8l7rpmv9s2y2rukn', 
        'object' : 'draft', 
        'reply_to' : [], 
        'reply_to_message_id' : None, 
        'snippet' : '', 
        'starred' : False, 
        'subject' : 'Stay polish, stay hungary', 
        'thread_id' : 'clm33kapdxkposgltof845v9s', 
        'to' : [{ 
            'email' : 'helena@nylas.com', 
            'name' : 'Helena Handbasket', 
}], 
        'unread' : False, 
        'version' : 0, 
} 
    values = [(400, { 
        
}, "Couldn't send email"), (200, { 
        
}, json.dumps (body))] 
    def callback(request) : 
        payload = json.loads (request.body) 
        assert (payload ['draft_id'] == '2h111aefv8pzwzfykrn7hercj') 
        assert (payload ['version'] == 0) 
        return values.pop () 
responses.add_callback (responses.POST, (API_URL + '/send/'), callback = values, content_type = 'application/json') 

    
    

    Fix the buggy line: responses.add_callback (responses.POST, (API_URL + '/send/'), callback = values, content_type = 'application/json')
assistant
#Here is Python code to fix the buggy line: responses.

responses.add_callback (responses.POST, (API_URL + '/send/'), callback = callback, content_type = 'application/json')