docs: @Override
      public SpecTopic getClosestTopic(final SpecTopic topic, final SpecNode callerNode, final boolean checkParentNode) {
          final SpecTopic retValue = super.getClosestTopic(topic, callerNode, checkParentNode);
          if (retValue != null) {
              return retValue;
          } else {
              // Look up the metadata topics
              final ContentSpec contentSpec = getContentSpec();
              for (final Node contentSpecNode : contentSpec.getNodes()) {
                  if (contentSpecNode instanceof KeyValueNode && ((KeyValueNode) contentSpecNode).getValue() instanceof SpecTopic) {
                      final SpecTopic childTopic = (SpecTopic) ((KeyValueNode) contentSpecNode).getValue();
                      if (childTopic == topic || childTopic.getId().equals(topic.getId())) {
                          return childTopic;
                      }
                  }
              }
  
              return null;
          }
      }