req1.setArtifact(new DefaultArtifact("ut.simple:artifact:1.0"));
        req1.addRepository(newTestRepository());

        ArtifactRequest req2 = new ArtifactRequest();
        req2.setArtifact(new DefaultArtifact("ut.simple:artifact:zip:1.0"));
        req2.addRepository(newTestRepository());

        ArtifactRequest req3 = new ArtifactRequest();

type uaTransport struct {
	ua string
	rt http.RoundTripper
}

func (u *uaTransport) RoundTrip(req *http.Request) (*http.Response, error) {
	req2 := req.Clone(req.Context())
	req2.Header.Set("User-Agent", u.ua)
	return u.rt.RoundTrip(req2)
}

// WithUserAgent wraps an existing transport with custom User-Agent
func WithUserAgent(rt http.RoundTripper, getUA func() string) http.RoundTripper {

        long seq1 = registration.getNextSequenceNumber();
        long seq2 = registration.getNextSequenceNumber();
        long seq3 = registration.getNextSequenceNumber();

        assertEquals(1, seq1);
        assertEquals(2, seq2);
        assertEquals(3, seq3);
        assertTrue(seq2 > seq1);
        assertTrue(seq3 > seq2);
    }

    @Test
    void testHeartbeatUpdate() throws InterruptedException {