## TODO

* [ ] more complete functions and aggregations
* [ ] more complete tx tests
* [ ] graph algorithms
  * [ ] bfs
  * [ ] dfs
  * [ ] shortest path
  * [ ] A*
  * [ ] Yen's k-shortest
  * [ ] all-pairs shortest path
  * [ ] single-source shortest path
  * [ ] minimum spanning tree
  * [ ] random walking
  * [x] degree centrality
  * [ ] closeness centrality
  * [ ] betweenness centrality
  * [ ] pagerank
  * [ ] triangle counting
  * [ ] strongly connected components
  * [ ] connected components
  * [ ] label propagation
  * [ ] louvain modularity
* [ ] direct loading of data