nl_tokens: Yanked from https : // git . io / vS8DV re - used under CC0 with some tiny modifications
pl_tokens: function isError ( value ) { switch ( Object . prototype . toString . call ( value ) ) { case '[object Error]' : return <mask> ; case '[object Exception]' : return true ; case '[object DOMException]' : return true ; default : return value instanceof Error ; } }