public function removeTerm($term_name, $taxonomy = '')
    {
        if (! $term = $this->getTerm($term_name, $taxonomy))
            return null;

        if ($taxonomy) {
            $taxonomy = $this->taxonomies->where('taxonomy', $taxonomy)->where('term_id', $term->id)->first();
        } else {
            $taxonomy = $this->taxonomies->where('term_id', $term->id)->first();
        }

        return $this->taxed()->where('taxonomy_id', $taxonomy->id)->delete();
    }