def lock(self):
        if not self._locked:
            self._file = open(os.path.join(self._path, '.mh_sequences'), 'rb+')
            _lock_file(self._file)
            self._locked = True
The set action can change the value of the proper attribute of a thing
dataset/ETHPy150Open babble/babble/include/jython/Lib/mailbox.py/MH.lock--crossover with--dataset/ETHPy150Open twisted/imaginary/imaginary/test/test_set.py/SetTests.test_commonNoun