nl_tokens: Check for the existence of given a key if the key is present at the current level return true otherwise walk up the parent hierarchy and try again . If no matching key is found return false .
pl_tokens: function ( key ) { var dict = this . dict ; if ( dict . hasOwnProperty ( <mask> ) ) { return true ; } if ( this . parent ) { return this . parent . has ( key ) ; } return false ; }