public function getFilters()
    {
        // default filters are empty
        $filters = [];

        // if custom filters have been set, use them
        if (!is_null($this->filters)) {
            return $this->filters;
        }

        // if no custom filters have been set, and there are
        // Taxonomies assigned to the PostType
        if (is_null($this->filters) && !empty($this->taxonomies)) {
            // create filters for each taxonomy assigned to the PostType
            return $this->taxonomies;
        }

        return $filters;
    }