How to use the ifcfg.Parser function in ifcfg

def test_cp1252_non_utf8_byte(self):
        """
        Tests that things are still working when using this bizarre encoding
        """

        ifcfg.distro = "Windows"
        ifcfg.Parser = ifcfg.get_parser_class()

        self.assertTrue(issubclass(ifcfg.Parser, WindowsParser))

        parser = ifcfg.get_parser()
        interfaces = parser.interfaces

        self.assertIn("Ethernet adapter Local Area Connection 2", interfaces.keys())
        self.assertIn("Tunnel adapter isatap.lan", interfaces.keys())
        self.assertIn("Tunnel adapter Teredo Tunneling Pseudo-Interface", interfaces.keys())

        self.assertEqual(len(interfaces.keys()), 3)

        eq_(interfaces['Ethernet adapter Local Area Connection 2']['inet'], '10.0.2.15')
        self.assertEqual(
            len(interfaces['Ethernet adapter Local Area Connection 2']['inet6']),
            0

def test_macosx2(self):
        ifcfg.distro = 'MacOSX'
        ifcfg.Parser = ifcfg.get_parser_class()
        parser = ifcfg.get_parser(ifconfig=ifconfig_out.MACOSX2)
        interfaces = parser.interfaces
        self.assertEqual(len(interfaces.keys()), 9)
        eq_(interfaces['lo0']['inet'], '127.0.0.1')
        eq_(interfaces['lo0']['inet4'], ['127.0.0.1', '127.0.1.99'])
        eq_(interfaces['lo0']['netmask'], '255.0.0.0')

def test_linux(self):
        ifcfg.Parser = UnixIPParser
        parser = ifcfg.get_parser(ifconfig=ip_out.LINUX)
        interfaces = parser.interfaces
        # Unconnected interface
        eq_(interfaces['enp0s25']['ether'], 'a0:00:00:00:00:00')
        eq_(interfaces['enp0s25']['inet'], None)
        # Connected interface
        eq_(interfaces['wlp3s0']['ether'], 'a0:00:00:00:00:00')
        eq_(interfaces['wlp3s0']['inet'], '192.168.12.34')
        eq_(interfaces['wlp3s0']['inet4'], ['192.168.12.34'])
        eq_(interfaces['wlp3s0']['inet6'], ['fd37:a521:ada9::869', 'fd37:a521:ada9:0:b9f7:44f8:bb19:c78c', 'fd37:a521:ada9:0:9073:a91:d14f:8087', 'fe80::205f:5d09:d0da:7aed'])
        eq_(interfaces['wlp3s0']['broadcast'], '192.168.12.255')
        eq_(interfaces['wlp3s0']['netmask'], '/24')
        eq_(interfaces['wlp3s0']['mtu'], '1500')
        # Connected interface
        eq_(interfaces['enp6s0.2']['ether'], '00:73:00:5c:09:9a')
        eq_(interfaces['enp6s0.2']['inet'], '10.2.2.253')

def test_illegal(self):
        ifcfg.distro = 'Linux'
        ifcfg.Parser = LinuxParser
        ifcfg.get_parser(ifconfig=ifconfig_out.ILLEGAL_OUTPUT)