@Override public boolean equals(Object o) {
      if (o == this) return true;
      if (!(o instanceof TraceIdTimestamp)) return false;
      TraceIdTimestamp that = (TraceIdTimestamp) o;
      return lowTraceId.equals(that.lowTraceId) && timestamp == that.timestamp;
    }
Returns service names orphaned by removing the trace ID
zipkin/src/main/java/zipkin2/storage/InMemoryStorage.java