code: function (e) {
          // save a reference to this to use in the timeout
          var self = this;
          // call the super function
          this._super(me.DroptargetEntity, "draw", [e]);
          // indicate a succesful drop
          this.color = "green";
          // set the color back to red after a second
          window.setTimeout(function () {
              self.color = "red";
          }, 1000);
      }
docs: drop overwrite function