Graph<E>.from  constructor 
- WalkableBase<
E> walkable, { - bool directed,
 
Creates a AdjacencyListGraph graph from a walkable.
Each edge in the walkable is added to the graph, similar to calling:
final graph = Graph<E>();
graph.addEdges(walkable.edges);
If directed is true, which is the default, the graph is directed, i.e.
an edge has an explicit source and a target node. If directed is
false, the graph is undirected, and the inverse of an edge is also an
edge.
Implementation
factory Graph.from(
  WalkableBase<E> walkable, {
  bool directed,
}) = AdjacencyListGraph<E>.from;