@Test void errorTagAdded() {
    DependencyLinkV2SpanIterator iterator =
        iterator(
            newRecord()
                .values(traceIdHigh, traceId, parentId, spanId, "error", TYPE_STRING, "foo"));
    Span span = iterator.next();

    assertThat(span.tags()).containsOnly(entry("error", ""));
  }
"sr" is only applied when the local span is acting as a server
zipkin-storage/mysql-v1/src/test/java/zipkin2/storage/mysql/v1/DependencyLinkV2SpanIteratorTest.java