@Override
  public synchronized Call<List<DependencyLink>> getDependencies(long endTs, long lookback) {
    if (endTs <= 0) throw new IllegalArgumentException("endTs <= 0");
    if (lookback <= 0) throw new IllegalArgumentException("lookback <= 0");

    Set<String> lowTraceIdsInRange =
      lowTraceIdsInRange(spansByTraceIdTimestamp.keySet(), endTs, lookback);
    List<DependencyLink> links = getDependencyLinks(lowTraceIdsInRange);
    return Call.create(links);
  }
Used for testing. Returns all dependency links unconditionally.
zipkin/src/main/java/zipkin2/storage/InMemoryStorage.java