@Override
	public void set(String category, String comment) {
		checkDeleted();

		if (category == null)
			category = "";
		if (comment == null)
			comment = "";
		if (!comment.equals(record.getString(BookmarkDBAdapter.COMMENT_COL)) ||
			!category.equals(record.getString(BookmarkDBAdapter.CATEGORY_COL))) {

			record.setString(BookmarkDBAdapter.CATEGORY_COL, category);
			record.setString(BookmarkDBAdapter.COMMENT_COL, comment);
			mgr.bookmarkChanged(this);
		}
	}
Returns bookmark type or null if type has been removed.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/bookmark/BookmarkDB.java