check this implementation https://blogs.windows.com/msedgedev/2017/04/19/modernizing-dom-tree-microsoft-edge/ https://blogs.windows.com/msedgedev/2017/04/19/mod

check this implementation https://blogs.windows.com/msedgedev/2017/04/19/modernizing-dom-tree-microsoft-edge/ https://blogs.windows.com/msedgedev/2017/04/19/modernizing-d... graph doesn't mean multiple parents all the time. if you have references of other nodes in current node data(not just as children) as long as you can travel across Data structure, enough to say it as graph structure.