public RequestMessage.Builder buildMessage(final RequestMessage.Builder builder) {
        return builder;
    }
Makes any initial changes to the builder and returns the constructed {@link RequestMessage}.  Implementers
may choose to override this message to append data to the request before sending.  By default, this method
will simply return the {@code builder} passed in by the caller.
gremlin-driver/src/main/java/org/apache/tinkerpop/gremlin/driver/Client.java