test(hansbug): add compare with facebook nest library
dev(hansbug): add keys, values and items for TreeValue class
dev(hansbug): update the tree print system
dev(hansbug): add support for treevalue[potc]
dev(hansbug): add delay feature in treevalue && add mode and missing option to union and subside
doc(hansbug): add practice pages
doc(hansbug): add new benchmark and graphs of speed performance