GitLab

* WIP

* header

* WIP .cc

* WIP

* transpose

* wip

* immutable graph .h and .cc

* WIP: nodeflow.cc

* compile

* remove all tmp dl managed ctx; they caused refcount issue

* one simple test

* WIP: testing

* test_graph

* fix graph index

* fix bug in sampler; pass pytorch utest

* WIP on mxnet

* fix lint

* fix mxnet unittest w/ unfortunate workaround

* fix msvc

* fix lint

* SliceRows and test_nodeflow

* resolve reviews

* resolve reviews

* try fix win ci

* try fix win ci

* poke win ci again

* poke

* lazy multigraph flag; stackoverflow error

* revert node subgraph test

* lazy object

* try fix win build

* try fix win build

* poke ci

* fix build script

* fix compile

* add a todo

* fix reviews

* fix compile