I'm using pact-jvm version 3.5.x (an old version due to legacy system), and want to do a Message test that verifies the metadata that my consumer publishes. According to https://docs.pact.io/implementation_guides/jvm/provider/junit#example-of-message-test-that-verifies-metadata, I should be using MessageAndMetadata however it's not available in the library, presumably because it's an older version. What other ways can I use to verify the metadata?

You could perhaps back port the change from a later version?