docs: public void setAuthorGroup(final SpecTopic authorGroup) {
          if (authorGroup == null && this.authorGroup == null) {
              return;
          } else if (authorGroup == null) {
              removeChild(this.authorGroup);
              this.authorGroup = null;
          } else if (this.authorGroup == null) {
              authorGroup.setTopicType(TopicType.AUTHOR_GROUP);
              this.authorGroup = new KeyValueNode<SpecTopic>(CommonConstants.CS_AUTHOR_GROUP_TITLE, authorGroup);
              appendChild(this.authorGroup, false);
          } else {
              authorGroup.setTopicType(TopicType.AUTHOR_GROUP);
              this.authorGroup.setValue(authorGroup);
          }
      }