public boolean doApplyTo(DomainObject obj, TaskMonitor monitor) {
			monitor.initialize(bookmarkList.size());
			BookmarkManager mgr = ((Program) obj).getBookmarkManager();
			for (BookmarkRowObject rowObject : bookmarkList) {
				Bookmark bookmark = mgr.getBookmark(rowObject.getKey());
				mgr.removeBookmark(bookmark);
				monitor.incrementProgress(1);
				if (monitor.isCancelled()) {
					break;
				}
			}
			return true;
		}
Class for the combo box model to hold list of categories.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/bookmark/BookmarkProvider.java