public static <T> Values<T> of(Iterable<T> elems) {
    return new Values<>(elems, Optional.absent(), Optional.absent(), false);
  }
@Test
  public void testSourceGetOutputCoderReturnsConstructorCoder() throws Exception {
    Coder<Integer> coder = VarIntCoder.of();
    CreateSource<Integer> source =
        CreateSource.fromIterable(ImmutableList.of(1, 2, 3, 4, 5, 6, 7, 8), coder);

    Coder<Integer> defaultCoder = source.getOutputCoder();
    assertThat(defaultCoder, equalTo(coder));
  }