@Test
public void invokeArrayOfStrings() {

    FunctionTestUtil.assertResult(maxFunction.invoke(new Object[]{"a"}), "a");
    FunctionTestUtil.assertResult(maxFunction.invoke(new Object[]{"a", "b", "c"}), "c");
    FunctionTestUtil.assertResult(maxFunction.invoke(new Object[]{"a", "c", "b"}), "c");
    FunctionTestUtil.assertResult(maxFunction.invoke(new Object[]{"c", "a", "b"}), "c");
}