code: def validate_confusables(value):
      
      if not isinstance(value, six.text_type):
          return
      if confusables.is_dangerous(value):
          raise ValidationError(CONFUSABLE, code='invalid')
docs: Validator which disallows 'dangerous' usernames likely to
      represent homograph attacks.
  
      A username is 'dangerous' if it is mixed-script (as defined by
      Unicode 'Script' property) and contains one or more characters
      appearing in the Unicode Visually Confusable Characters file.