AttributeError: 'module' object has no attribute 'UserEntityEntry'

[dajor]

File "tt.py", line 40, in main
apiai.UserEntityEntry('Firefox', ['Firefox']),
AttributeError: 'module' object has no attribute 'UserEntityEntry'

In the example

def main():
ai = apiai.ApiAI(CLIENT_ACCESS_TOKEN,'')

 # some unuque session id for user identification
 session_id = uuid.uuid4().hex

 entries = [
     apiai.UserEntityEntry('Firefox', ['Firefox']),
     apiai.UserEntityEntry('XCode', ['XCode']),
     apiai.UserEntityEntry('Sublime Text', ['Sublime Text'])
 ]