Update article.languages

def pre_save_title(instance, **kwargs):
    ''' Update article.languages
    '''
    if instance.article.languages:
        languages = instance.article.languages.split(',')
    else:
        languages = []
    if instance.language not in languages:
        languages.append(instance.language)
        instance.article.languages = ','.join(languages)
        instance.article._publisher_keep_state = True
        instance.article.save(no_signals=True)