nl_tokens: From MDN site https : // developer . mozilla . org / en - US / docs / Web / JavaScript / Reference / Global_Objects / Array / filter
pl_tokens: function filterFn ( ) { if ( ! <mask> . prototype . filter ) { Array . prototype . filter = function ( fun /*, thisArg*/ ) { 'use strict' ; if ( this === void 0 || this === null ) { throw new TypeError ( ) ; } var t = Object ( this ) ; var len = t . length >>> 0 ; if ( typeof fun !== 'function' ) { throw new TypeError ( ) ; } var res = [ ] ; var thisArg = arguments . length >= 2 ? arguments [ 1 ] : void 0 ; for ( var i = 0 ; i < len ; i ++ ) { if ( i in t ) { var val = t [ i ] ; // NOTE: Technically this should Object.defineProperty at //       the next index, as push can be affected by //       properties on Object.prototype and Array.prototype. //       But that method's new, and collisions should be //       rare, so use the more-compatible alternative. if ( fun . call ( thisArg , val , i , t ) ) { res . push ( val ) ; } } } return res ; } ; } }