code: void inspectStorageDirs(FSImageStorageInspector inspector)
        throws IOException {
  
      // Process each of the storage directories to find the pair of
      // newest image file and edit file
      for (Iterator<StorageDirectory> it = dirIterator(); it.hasNext();) {
        StorageDirectory sd = it.next();
        inspector.inspectDirectory(sd);
      }
    }
docs: Iterate over all current storage directories, inspecting them
  with the given inspector.