* copy graph index to shared memory.
* fix.
* fix.
* fix.
* use a diff name for in-csr and out-csr.
* fix lint.
* remove print.
* add test.
* add comments.
* to simple
* WIP: multigraph flag
* graph index refactor; pass basic testing
* graph index refactor; pass basic testing
* fix bug in to_simple; pass torch test
* fix mx utest
* fix example
* fix lint
* fix ci
* poke ci
* poke ci
* WIP
* poke ci
* poke ci
* poke ci
* change ci workspace
* poke ci
* poke ci
* poke ci
* poke ci
* delete ci
* use enum for multigraph flag