def render(self, context):
        url = super(RevCanonical, self).render(context)
        if url:
            return mark_safe('<link rev="canonical" href="%s">' % url)
        else:
            return ''
dataset/ETHPy150Open bfirsh/django-shorturls/src/shorturls/templatetags/shorturl.py/RevCanonical.render/original