protected static function _setMapTree($method, $path, $content)
    {
        $path     = self::_pathParse(self::$_filter['prefix'].$path);
        $callback = is_string($content) ?
                    self::_namespaceParse('\\'.self::$_filter['namespace'].$content) : $content;
        
        if (self::_isVariableRoute($path)) { // is variable route
            $path = self::_variablePathReplace($path);
            self::$_variable_map_tree[$path][strtoupper($method)] = $callback;
        } else { // is usual route
            self::$_map_tree[$path][strtoupper($method)] = $callback;
        }

        self::$_middleware_map_tree[$path][strtoupper($method)] = self::$_filter['middleware'];  
    }