assertEquals(true, ClassUtils.isInnerClass(new Cloneable() { }.getClass()));
    public void test_isInnerClass_Class() {        assertEquals(true, ClassUtils.isInnerClass(Inner.class));        assertEquals(true, ClassUtils.isInnerClass(Map.Entry.class));        assertEquals(false, ClassUtils.isInnerClass(this.getClass()));        assertEquals(false, ClassUtils.isInnerClass(String.class));        try {            ClassUtils.isInnerClass(null);            fail();        } catch (IllegalArgumentException ex) {}    }