def test_deleteCharacter(self):
        """
        L{ServerProtocol.deleteCharacter} writes the control sequence
        containing the number of characters to delete and ending in
        L{CSFinalByte.DCH}
        """
        self.protocol.deleteCharacter(4)
        self.assertEqual(self.transport.value(),
                         self.CSI + b'4' + CSFinalByte.DCH.value)

        L{ServerProtocol.deleteCharacter} writes the control sequence
        containing the number of characters to delete and ending in
        L{CSFinalByte.DCH}
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/test/test_insults.py