nl_tokens: Extends object a by mutably adding to it the properties of object b .
pl_tokens: function extend ( a , b , thisArg ) { forEach ( b , function assignValue ( val , key ) { if ( thisArg && typeof val === 'function' ) { a [ key ] = bind ( val , thisArg ) ; } else { a [ <mask> ] = val ; } } ) ; return a ; }