pub trait VertexTypes<'a, G: WithVertex> {
type VertexIter: Iterator<Item = Vertex<G>>;
type OutNeighborIter: Iterator<Item = Vertex<G>>;
}pub trait VertexTypes<'a, G: WithVertex> {
type VertexIter: Iterator<Item = Vertex<G>>;
type OutNeighborIter: Iterator<Item = Vertex<G>>;
}