Equal returns true if graph a and graph b meet the following rules, otherwise, it returns false: - a.IsDirected() == b.IsDirected() - a.AllowsSelfLoops() == b.AllowsSelfLoops() - a.Nodes() and b.Nodes() are equal according to set.Equal - a.Edges() and b.Edges() are equal according to set.Equal This method should be used over ==, the behaviour of which is undefined.