>>> c.foo.bar.create_index('foo')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "pymongo/collection.py", line 1058, in create_index
    indexes=[index])
  File "pymongo/database.py", line 410, in command
    read_preference, **kwargs)[0]
  File "pymongo/database.py", line 321, in _command
    for doc in cursor:
  File "pymongo/cursor.py", line 988, in next
    if len(self.__data) or self._refresh():
  File "pymongo/cursor.py", line 932, in _refresh
    self.__uuid_subtype))
  File "pymongo/cursor.py", line 875, in __send_message
    self.__compile_re)
  File "pymongo/helpers.py", line 110, in _unpack_response
    error_object)
pymongo.errors.OperationFailure: database error: unrecognized command: createIndexes

>>> c.foo.add_user("foo", "bar")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "pymongo/database.py", line 755, in add_user
    read_preference=ReadPreference.PRIMARY)
  File "pymongo/database.py", line 410, in command
    read_preference, **kwargs)[0]
  File "pymongo/database.py", line 321, in _command
    for doc in cursor:
  File "pymongo/cursor.py", line 988, in next
    if len(self.__data) or self._refresh():
  File "pymongo/cursor.py", line 932, in _refresh
    self.__uuid_subtype))
  File "pymongo/cursor.py", line 875, in __send_message
    self.__compile_re)
  File "pymongo/helpers.py", line 110, in _unpack_response
    error_object)
pymongo.errors.OperationFailure: database error: unrecognized command: usersInfo

>>> c.foo.remove_user("foo")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "pymongo/database.py", line 807, in remove_user
    writeConcern=self._get_wc_override())
  File "pymongo/database.py", line 437, in command
    uuid_subtype, compile_re, **kwargs)[0]
  File "pymongo/database.py", line 337, in _command
    for doc in cursor:
  File "pymongo/cursor.py", line 1038, in next
    if len(self.__data) or self._refresh():
  File "pymongo/cursor.py", line 982, in _refresh
    self.__uuid_subtype))
  File "pymongo/cursor.py", line 925, in __send_message
    self.__compile_re)
  File "pymongo/helpers.py", line 109, in _unpack_response
    error_object)
pymongo.errors.OperationFailure: database error: unrecognized command: dropUser