public static <T> Global<T> globally() {
    return new Global<>();
  }
@Test
  @Category(NeedsRunner.class)
  public void testGroupGlobally() {
    Collection<Basic> elements =
        ImmutableList.of(
            Basic.of("key1", 1, "value1"),
            Basic.of("key1", 1, "value2"),
            Basic.of("key2", 2, "value3"),
            Basic.of("key2", 2, "value4"));

    PCollection<Iterable<Basic>> grouped =
        pipeline.apply(Create.of(elements)).apply(Group.globally());
    PAssert.that(grouped).satisfies(actual -> containsSingleIterable(elements, actual));
    pipeline.run();
  }