@Test
public void testCreateJointSkin() {

    JOINT.setType(null);
    assertNull(skinFactory.createJointSkin(null));
    assertTrue(skinFactory.createJointSkin(JOINT) instanceof DefaultJointSkin);
    JOINT.setType(JOINT_TYPE);
    assertTrue(skinFactory.createJointSkin(JOINT) instanceof DefaultJointSkin);
    skinFactory.setJointSkin(JOINT_TYPE, CustomJointSkin.class);
    assertTrue(skinFactory.createJointSkin(JOINT) instanceof CustomJointSkin);
}