code: function() {
          var me = this,
              isDirty = me.isDirty();
          if (isDirty !== me.wasDirty) {
              me.fireEvent('dirtychange', me, isDirty);
              me.onDirtyChange(isDirty);
              me.wasDirty = isDirty;
          }
      }
docs: Checks the {@link #isDirty} state of the field and if it has changed since the last time it was checked,
  fires the {@link #dirtychange} event.