@Test void whenSrAndCaServiceExists_caIsThePeer() {
    DependencyLinkV2SpanIterator iterator =
        iterator(
            newRecord().values(traceIdHigh, traceId, parentId, spanId, "ca", TYPE_BOOLEAN, "s1"),
            newRecord().values(traceIdHigh, traceId, parentId, spanId, "sr", -1, "s2"));
    Span span = iterator.next();

    assertThat(span.kind()).isEqualTo(Span.Kind.SERVER);
    assertThat(span.localServiceName()).isEqualTo("s2");
    assertThat(span.remoteServiceName()).isEqualTo("s1");
  }
"ca" indicates the peer, which is a client in the case of a server span
zipkin-storage/mysql-v1/src/test/java/zipkin2/storage/mysql/v1/DependencyLinkV2SpanIteratorTest.java