@Override public List<List<Span>> map(List<List<Span>> input) {
      if (hasClashOnLowerTraceId(input)) {
        return FilterTraces.create(request).map(input);
      }
      return input;
    }
Filters the mutable input client-side when there's a clash on lower 64-bits of a trace ID.

@see FilterTraces
zipkin/src/main/java/zipkin2/storage/StrictTraceId.java