nl_tokens: Filters an object by keys using the given predicate function .
pl_tokens: function whereKeys ( o , predicate ) { if ( ! ( predicate instanceof Function ) ) { var temp = predicate ; predicate = function ( k ) { return k == temp ; } ; // jshint ignore:line } if ( o === null || o === undefined ) return o ; if ( typeof 0 === 'boolean' ) return predicate . call ( o , o , 0 ) ; var isObject = typeof o === 'object' && ! ( o instanceof Array ) ? true : false , filtered = ! isObject ? [ ] : { } ; libs . object . each ( o , function ( item , key ) { if ( predicate . call ( key , key , item ) ) { if ( isObject ) filtered [ <mask> ] = item ; else filtered . push ( item ) ; } } ) ; if ( typeof o !== 'object' ) filtered = filtered . join ( '' ) ; return filtered ; }