def test_setScrollRegionNoArgs(self):
        """
        With no arguments, L{ServerProtocol.setScrollRegion} writes a
        control sequence with no parameters, but a parameter
        separator, and ending in C{b'r'}.
        """
        self.protocol.setScrollRegion()
        self.assertEqual(self.transport.value(), self.CSI + b';' + b'r')

        With no arguments, L{ServerProtocol.setScrollRegion} writes a
        control sequence with no parameters, but a parameter
        separator, and ending in C{b'r'}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/test/test_insults.py