GitLab

* add in_subgraph on DistGraph.

* check in more.

* fix test.

* add comments.

* fix test.

* update test.

* update.

* rename.

* update comment

* fix test

* optimize sampling neighbors from the local partition.

* fix minior bugs.

* fix lint

* overlap local sampling and remote sampling.

* fix.

* fix lint.

* fix a potential bug.
Co-authored-by: Chao Ma <mctt90@gmail.com>

* fix

* test1111

* 111

* 111

* fff

* lint

* 111

* lint

* lint

* 111

* fijx

* 111

* fix

* 111

* commit

* 111

* 111

* lint

* fix typo

* fix

* lint

* fix

* 111

* support mxnet

* support mxnet

* lint

* remove print

* fix

* fix test.

* fix test.

* fix test.

* try to fix an undetermistic error.
Co-authored-by: Chao Ma <mctt90@gmail.com>
Co-authored-by: Da Zheng <zhengda1936@gmail.com>