code: public void setMenuIconProgress(float progress) {
          mMenuBtnDrawable.setProgress(progress);
          if (progress == 0) {
              closeMenu(false);
          } else if (progress == 1.0) {
              openMenu(false);
          }
      }
docs: <p/>
  Enables clients to directly manipulate
  the menu icon's progress.
  <p/>
  Useful for custom animation/behaviors.
  
  @param progress the desired progress of the menu
  icon's rotation: 0.0 == hamburger
  shape, 1.0 == back arrow shape