@Override public synchronized Call<List<Span>> getTrace(String traceId) {
    traceId = Span.normalizeTraceId(traceId);
    List<Span> spans = spansByTraceId(lowTraceId(traceId));
    if (spans.isEmpty()) return Call.emptyList();
    if (!strictTraceId) return Call.create(spans);

    List<Span> filtered = new ArrayList<>(spans);
    Iterator<Span> iterator = filtered.iterator();
    while (iterator.hasNext()) {
      if (!iterator.next().traceId().equals(traceId)) {
        iterator.remove();
      }
    }
    return Call.create(filtered);
  }
Used for testing. Returns all dependency links unconditionally.
zipkin/src/main/java/zipkin2/storage/InMemoryStorage.java