code: public static Builder builder(Type type, long messageId) {
      return new AutoValue_MessageEvent.Builder()
          .setType(Utils.checkNotNull(type, "type"))
          .setMessageId(messageId)
          // We need to set a value for the message size because the autovalue requires all
          // primitives to be initialized.
          .setUncompressedMessageSize(0)
          .setCompressedMessageSize(0);
    }
docs: Returns a new {@link Builder} with default values.
  
  @param type designates whether this is a send or receive message.
  @param messageId serves to uniquely identify each message.
  @return a new {@code Builder} with default values.
  @throws NullPointerException if {@code type} is {@code null}.
  @since 0.12