pub trait GraphNodeMutIndexable<N>: GraphBase + GraphNodeIndexable<N> {
// Required method
fn node_mut(&mut self, id: Self::NodeID) -> &mut N;
}
pub trait GraphNodeMutIndexable<N>: GraphBase + GraphNodeIndexable<N> {
// Required method
fn node_mut(&mut self, id: Self::NodeID) -> &mut N;
}