GitLab

* sort

* sort in parallel.

* fix a bug in sorting adj

* rename.

* add more comments.

* accelerate GetData

* fix tests.

* avoid sorting multiple times.

* add test.

* change back.

* sort.

* add sort_csr.

* Fix a bug.

* fix.

* revert modifcation.

* rename

* speed up EdgeIds.