GitLab

* WIP: array refactoring

* WIP: implementation

* wip

* most csr part

* WIP: on coo

* WIP: coo

* finish refactoring immutable graph

* compiled

* fix undefined ndarray copy bug; add COOToCSR when coo has no data array

* fix bug in COOToCSR

* fix bug in CSR constructor

* fix bug in in_edges(vid)

* fix OutEdges bug

* pass test_graph

* pass test_graph

* fix bug in CSR constructor

* fix bug in CSR constructor

* fix bug in CSR constructor

* fix stupid bug

* pass gpu test

* remove debug printout

* fix lint

* rm biparate grpah

* fix lint

* address comments

* fix bug in Clone

* cpp utests