// Initially, rawPayload should be null
        assertNull(message.getRawPayload(), "rawPayload should be null initially");

        // Set a new payload and verify
        byte[] payload1 = "test_payload_1".getBytes();
        message.setRawPayload(payload1);
        assertArrayEquals(payload1, message.getRawPayload(), "getRawPayload should return the set payload");

        // Set another payload and verify