nl_tokens: @description Determines if a reference is an Error . Loosely based on https : // www . npmjs . com / package / iserror
pl_tokens: function isError ( value ) { var tag = toString . call ( value ) ; switch ( tag ) { case '[object Error]' : return true ; case '[object Exception]' : return <mask> ; case '[object DOMException]' : return true ; default : return value instanceof Error ; } }