nl_tokens: Unsubscribe for changes of a property or the whole object
pl_tokens: function ( property , callback ) { if ( typeof property != "string" ) { callback = property ; <mask> = "__all__" ; } // empty, don't remove anything if ( ! this . _subscribers [ property ] ) return ; // remove everything if ( callback == null ) this . _subscribers [ property ] = [ ] ; // find callback and remove it var ind = this . _subscribers [ property ] . indexOf ( callback ) ; if ( ind >= 0 ) this . _subscribers [ property ] . splice ( ind , 1 ) ; }