public static function set($format, $mime, $definition = [])
    {
        $mime = $mime ? (array) $mime : ['text/html'];

        $definition += [
            'cast'       => true,
            'decode'     => null,
            'encode'     => null,
            'mime'       => $mime,
            'conditions' => []
        ];

        static::$_formats[$format] = $definition;
    }