def test_consumeLengthBorderCase1(self):
        """
        C{_consumeLength} works as expected if the length specification
        contains the value of C{MAX_LENGTH} (border case).
        """
        self.netstringReceiver._remainingData = b"12:"
        self.netstringReceiver.MAX_LENGTH = 12
        self.netstringReceiver._consumeLength()
        self.assertEqual(self.netstringReceiver._expectedPayloadSize, 13)

        C{_consumeLength} works as expected if the length specification
        contains the value of C{MAX_LENGTH} (border case).
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/protocols/test/test_basic.py