def __init__(self, headers=None, transportFactory=AbortableStringTransport):
        """
        @param headers: The headers for this response.  If L{None}, an empty
            L{Headers} instance will be used.
        @type headers: L{Headers}

        @param transportFactory: A callable used to construct the transport.
        """
        if headers is None:
            headers = Headers()
        self.headers = headers
        self.transport = transportFactory()

        @param headers: The headers for this response.  If L{None}, an empty
            L{Headers} instance will be used.
        @type headers: L{Headers}

        @param transportFactory: A callable used to construct the transport.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/test/test_agent.py