docs: static @Nullable String annotationQuery(Span span) {
      if (span.annotations().isEmpty() && span.tags().isEmpty()) return null;
  
      char delimiter = '░'; // as very unlikely to be in the query
      StringBuilder result = new StringBuilder().append(delimiter);
      for (Annotation a : span.annotations()) {
        if (a.value().length() > LONGEST_VALUE_TO_INDEX) continue;
  
        result.append(a.value()).append(delimiter);
      }
  
      for (Map.Entry<String, String> tag : span.tags().entrySet()) {
        if (tag.getValue().length() > LONGEST_VALUE_TO_INDEX) continue;
  
        result.append(tag.getKey()).append(delimiter); // search is possible by key alone
        result.append(tag.getKey() + "=" + tag.getValue()).append(delimiter);
      }
      return result.length() == 1 ? null : result.toString();
    }