code: public Crossfader withPanelSlideListener(SlidingPaneLayout.PanelSlideListener panelSlideListener) {
          this.mPanelSlideListener = panelSlideListener;
          if (mCrossFadeSlidingPaneLayout != null) {
              mCrossFadeSlidingPaneLayout.setPanelSlideListener(mPanelSlideListener);
          }
          return this;
      }
docs: set a PanelSlideListener used with the CrossFadeSlidingPaneLayout
  
  @param panelSlideListener
  @return