code: @SuppressWarnings("unchecked")
      private static void quietlyTryToMakeWindowNonOqaque(Window window) {
          try {
              Class  clazz  = Class.forName("com.sun.awt.AWTUtilities");
              Method method = clazz.getMethod("setWindowOpaque", java.awt.Window.class, Boolean.TYPE);
  
              method.invoke(clazz, window, false);
          } catch (Exception e) {
              // silently ignore this exception.
          }
      }
docs: Trys to invoke
  {@code com.sun.awt.AWTUtilities.setWindowOpaque(window,false)} on the
  given {@link Window}. This will only work when running with JRE 6 update
  10 or higher. This method will silently fail if the method cannot be
  invoked.
  
  @param window the {@code Window} to try and make non-opaque.