docs: public void importVocabulary(@NonNull VocabCache<T> vocabCache) {
          AtomicBoolean added = new AtomicBoolean(false);
          for (T element : vocabCache.vocabWords()) {
              if (this.addToken(element))
                  added.set(true);
          }
          //logger.info("Current state: {}; Adding value: {}", this.documentsCounter.get(), vocabCache.totalNumberOfDocs());
          if (added.get())
              this.documentsCounter.addAndGet(vocabCache.totalNumberOfDocs());
      }