fix ci

fix ci

address review cmmts, fix ci

remove dup code in datasets.cc

stage II tree_adapter

add test case for tree_adapter

use dfs to build tree

add more test case

add test case

fix ci

fix ci round 2

fix ci round 3

fix ci round 4

fix complie error

fix ci round 6

fix ci round 7

fix ci round 8

fix ci round 9