@Test
  void getOpenModules() {
    // Test if unmodifiable list is returned
    robot.interact(() -> {
      assertThrows(UnsupportedOperationException.class, () -> workbench.getOpenModules().remove(0));
    });
  }
Example of what happens in case of a closing dialog in the destroy() method of a module with
the user confirming the module should NOT get closed. Precondition: openModule tests pass.
workbenchfx-core/src/test/java/com/dlsc/workbenchfx/WorkbenchTest.java