'is_localizable == allowed to have translations. Make sure that isn\'t
violated.
For default language (en-US), is_localizable means it can have
translations. Enforce:
* is_localizable=True if it has translations
* if has translations, unable to make is_localizable=False
For non-default langauges, is_localizable must be False.'

def _clean_is_localizable(self):

    if (self.locale != settings.WIKI_DEFAULT_LANGUAGE):
        self.is_localizable = False
    if (self.parent and (self.parent.id != self.id) and (not self.parent.is_localizable)):
        raise ValidationError(('"%s":    parent    "%s"    is    not    localizable.' % (unicode(self), unicode(self.parent))))
    if (self.pk and (not self.is_localizable) and self.translations.exists()):
        raise ValidationError(('"%s":    document    has    %s    translations    but    is    not    localizable.' % (unicode(self), self.translations.count())))
