public static <T> LengthPrefixCoder<T> of(Coder<T> valueCoder) {
    checkNotNull(valueCoder, "Coder not expected to be null");
    return new LengthPrefixCoder<>(valueCoder);
  }
@Test
  public void testCoderIsSerializableWithWellKnownCoderType() throws Exception {
    CoderProperties.coderSerializable(LengthPrefixCoder.of(GlobalWindow.Coder.INSTANCE));
  }