@Override
  public void invalidateSelf() {
    if (mPreventInvalidateCount == 0) {
      super.invalidateSelf();
    }
  }
Creates a new fade drawable. The first layer is displayed with full opacity whereas all other
layers are invisible if allLayersVisible is false. Otherwise, all layers will be displayed with
full opacity.

@param layers layers to fade between
@param allLayersVisible true if all layers should be visible per default
@param actualImageLayer The index of the layer that contains the actual image
drawee/src/main/java/com/facebook/drawee/drawable/FadeDrawable.java