protected function addFilter($tag, $function_to_add, $priority = 10, $accepted_args = 1)
    {
        global $wp_filter;

        $idx                              = $this->filterBuildUniqueId($function_to_add);
        $wp_filter[$tag][$priority][$idx] = array('function' => $function_to_add, 'accepted_args' => $accepted_args);
        return true;
    }