Adam says so.

AdamSaysSo.js

(function() {

  // Duck punch that mofo
  $.Deferred = (function(deferredDef) {
    
    var slicer = [].slice;
  
    var adamSaysSo = function(truthy) {
      var args = slicer.call(arguments, 1);
      return this[truthy ? 'resolve' : 'reject'].apply(this, args);
    };
  
    return function(beforeStart) {
      var dfd = deferredDef(beforeStart);
      dfd.adamSaysSo = adamSaysSo;
      return dfd;
    };
  
  })($.Deferred);
  
  
  
  var dfd = new $.Deferred();
  return dfd;

})();

Oh, also that changes line #15