docs: public synchronized final void shutdown() throws RepositoryException {
          preShutdown();
  
          delegateWriter = NoOpQueryIndexWriter.INSTANCE;
          try {
              // Shutdown each of the provided indexes ...
              for (Map<String, AtomicIndex> byWorkspaceName : providedIndexesByWorkspaceNameByIndexName.values()) {
                  for (AtomicIndex provided : byWorkspaceName.values()) {
                      provided.shutdown(false);
                  }
              }
          } finally {
              providedIndexesByWorkspaceNameByIndexName.clear();
              providedIndexesByIndexNameByWorkspaceName.clear();
              postShutdown();
          }
      }