* Gets the count of documents matching the search criteria.
     *
     * @param callback The callback to configure the search request.
     * @return The number of matching documents.
     */
    public int getCount(final Consumer<SearchRequestBuilder> callback) {
        final TotalHits totalHits = getClient().get(c -> {
            final SearchRequestBuilder builder = c.prepareSearch(index).setSize(0).setTrackTotalHits(true);

                  if (!method.getDeclaringClass().equals(type)) {
                    return method.invoke(delegate, args);
                  }
                  checkState(started.getCount() == 1);
                  started.countDown();
                  try {
                    return method.invoke(delegate, args);
                  } catch (InvocationTargetException e) {

            @Override
            @ParametricNullness
            public K getElement() {
              return backingEntry.getKey();
            }

            @Override
            public int getCount() {
              return backingEntry.getValue().size();
            }
          };
        }
      };
    }

    @Override
    int distinctElements() {

            @Override
            @ParametricNullness
            public K getElement() {
              return backingEntry.getKey();
            }

            @Override
            public int getCount() {
              return backingEntry.getValue().size();
            }
          };
        }
      };
    }

    @Override
    public Spliterator<K> spliterator() {