Call<Void> newCall() {
      Call<Void> storeCall = bulkCallBuilder.build();
      if (pendingAutocompleteContexts.isEmpty()) return storeCall;
      return storeCall.handleError((error, callback) -> {
        for (AutocompleteContext context : pendingAutocompleteContexts) {
          consumer.delayLimiter.invalidate(context);
        }
        callback.onError(error);
      });
    }
Mutable type used for each call to store spans
zipkin-storage/elasticsearch/src/main/java/zipkin2/elasticsearch/ElasticsearchSpanConsumer.java