docs: private final void onEachIndex( ProvidedIndexOperation op ) {
          for (String workspaceName : workspaceNames()) {
              Collection<AtomicIndex> indexes = providedIndexesFor(workspaceName);
              if (indexes != null) {
                  for (AtomicIndex atomicIndex : indexes) {
                      assert atomicIndex.managed() != null;
                      assert atomicIndex.indexDefinition() != null;
                      op.apply(workspaceName, atomicIndex);
                  }
              }
          }
      }