public function getFetchOptions( &$humanReadable = null )
    {
        // aid to result fetching debugging
        // get fetch options in a human readable format
        if( func_num_args() ) {
            $humanReadable = [];
            $refl = new \ReflectionClass( __CLASS__ );
            foreach( $refl->getConstants() as $name => $value ) {
                if( $value & $this->fetchOptions and strpos( $name, 'DEFAULT' ) === false ) {
                    $humanReadable[] = $name;
                }
            }
        }
        return $this->fetchOptions;
    }