nl_tokens: Computes the union between the current array and all the array objects passed in . That is the set of unique objects present in all of the arrays .
pl_tokens: function union ( a ) { var args = libs . object . only ( libs . object . toArray ( arguments ) , 'array' ) ; var union = [ ] ; args . unshift ( a ) ; libs . object . each ( args , function ( array ) { libs . object . each ( array , function ( item ) { if ( union . indexOf ( <mask> ) === - 1 ) union . push ( item ) ; } ) ; } ) ; return union ; }