### Question:
StringUtil { public static String EnumNameToCssClassName(String name) { Args.notNull(name, "name"); return name.replace("_", "-").toLowerCase(); }  static String EnumNameToCssClassName(String name);  }### Answer:
@Test public void testEnumNameToCssClassNameNull() { assertThrows(IllegalArgumentException.class, () -> { StringUtil.EnumNameToCssClassName(null); }); }
@Test public void testEnumNameToCssClassName() { assertEquals("show-for-xxlarge-up", StringUtil.EnumNameToCssClassName("SHOW_FOR_XXLARGE_UP")); assertEquals("abc123", StringUtil.EnumNameToCssClassName("ABC123")); }