public static DisplayData from(HasDisplayData component) {
    checkNotNull(component, "component argument cannot be null");

    InternalBuilder builder = new InternalBuilder();
    builder.include(Path.root(), component);

    return builder.build();
  }
@Test
  public void testIncludeEmptyPath() {
    thrown.expectCause(isA(IllegalArgumentException.class));
    DisplayData.from(
        new HasDisplayData() {
          @Override
          public void populateDisplayData(DisplayData.Builder builder) {
            builder.include("", new NoopDisplayData());
          }
        });
  }