* moving heterograph index to another file
* node view
* python interfaces
* heterograph init
* bug fixes
* docstring for readonly
* more docstring
* unit tests & lint
* oops
* oops x2
* removed node/edge addition
* addressed comments
* lint
* rw on frames with one node/edge type
* homograph with underlying heterograph demo
* view is not necessary
* bugfix
* replace
* scheduler, builtins not working yet
* moving bipartite.h to header
* moving back bipartite to bipartite.h
* oops
* asbits and copyto for bipartite
* tested update_all and send_and_recv
* lightweight node & edge type retrieval
* oops
* sorry
* removing obsolete code
* oops
* lint
* various bug fixes & more tests
* UDF tests
* multiple type number_of_nodes and number_of_edges
* docstring fixes
* more tests
* going for dict in initialization
* lint
* updated api as per discussions
* lint
* bug
* bugfix
* moving back bipartite impl to cc
* note on views
* fix
* 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
* fix lint for graph_index.py
* pylint for base.py
* pylint for batched_graph.py
* pylint for frame.py; simplify and fix bugs in frame when index is slice type
* pylint for graph.py
* pylint for immutable_graph_index.py
* pylint for init.py
* pylint for rest files in root package
* pylint for _ffi package
* pylint for function package
* pylint for runtime package
* pylint for runtime.ir package
* add pylint to ci
* fix mx tests
* fix lint errors
* fix ci
* fix as requested
* fix lint
* multigraph support on graph index
* more tests
* multigraph flag, bugfix on clear & copy
* networkx interfaces
* including graph index tests in Jenkins
* node subgraph test
* edge subgraphs
* removing duplicates in pred/succ
* more explicit test and doc
* query source and destination from edge id
* subgraphindex
* renaming has_edge to has_edge_between, apply_edges adding eid
* send_on and send_and_recv_on
* DGLGraph edge subgraph
* merged send_on and send_and_recv_on
* change request
* removing hashmap
* creating multigraph by flag; mingw support
* changes per request
* reverting networkx auto multigraph discovery
* notes on send/send_and_recv on multigraphs
* changing test reducer from sum to max
* added a fixme note in spmv scheduler