code: private static ClassHierarchy loadClassHierarchy() {
      // TODO[JIRA REEF-400] The file should be created by AvroClassHierarchySerializer
      try (final InputStream chin = new FileInputStream(HelloCLR.CLASS_HIERARCHY_FILENAME)) {
        // TODO[JIRA REEF-400] Use AvroClassHierarchySerializer instead
        final ClassHierarchyProto.Node root = ClassHierarchyProto.Node.parseFrom(chin); // A
        final ClassHierarchy ch = new ProtocolBufferClassHierarchy(root);
        return ch;
      } catch (final IOException e) {
        final String message = "Unable to load class hierarchy.";
        LOG.log(Level.SEVERE, message, e);
        throw new RuntimeException(message, e);
      }
    }
docs: Loads the class hierarchy.
  
  @return