def __init__(self):
        """
        Create a fake sender and initialize the list of received boxes and
        unhandled errors.
        """
        self.sentBoxes = []
        self.unhandledErrors = []
        self.expectedErrors = 0

        Create a fake sender and initialize the list of received boxes and
        unhandled errors.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_amp.py