Whenever the edges of a graph are assigned a capacity it is possible to compute the maximum flow and the minimum cut of the graph. Whenever the edges of a graph are assigned a weight it is possible to find shortest paths in the graph. If one wants to perform these computations on a graph where none of its edges have been assigned a capacity or a weight, then the edges are taken to have a capacity or weight of one, and the computations are carried out accordingly.
The flow-based and shortest-paths algorithms and the resulting functionalities are fully documented in Chapter MULTIGRAPHS, Sections Maximum Flow and Minimum Cut and Distances, Shortest Paths and Minimum Weight Trees respectively.