def test_insertLine(self):
        """
        L{ServerProtocol.insertLine} writes the control sequence
        containing the number of lines to insert and ending in
        L{CSFinalByte.IL}
        """
        self.protocol.insertLine(5)
        self.assertEqual(self.transport.value(),
                         self.CSI + b'5' + CSFinalByte.IL.value)

        L{ServerProtocol.insertLine} writes the control sequence
        containing the number of lines to insert and ending in
        L{CSFinalByte.IL}
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/test/test_insults.py