def METHOD_NAME(self):
    """
    test corner cases in the init method
    """
    with self.assertRaises(ValueError) as ve:
        self.text.tag_add('console', '1.0', '1.end')
        p = self.get_parser('1.5')
    self.assertIn('precedes', str(ve.exception))
    # test without ps1
    self.editwin.context_use_ps1 = False
    # number of lines lesser than 50
    p = self.get_parser('end')
    self.assertEqual(p.rawtext, self.text.get('1.0', 'end'))
    # number of lines greater than 50
    self.text.insert('end', self.text.get('1.0', 'end')*4)
    p = self.get_parser('54.5')