@Override
    public void setLeftWidth(float leftWidth) {
        drawable1.setLeftWidth(leftWidth);
        drawable2.setLeftWidth(leftWidth);
    }
@param drawable1 the drawable to be drawn on the bottom of the stack
@param drawable2 the drawable to be drawn on the top of the stack
core/src/com/ray3k/skincomposer/StackedDrawable.java