{"ast_node_type":"other","tokens":[{"end":96,"kind":"keyword","start":0,"text":"//"}]}
    // This is basically a `HashMap<N, (Vec<N>, If<BR, Vec<N>>)>` -- a map from a node index, to
pub struct VecGraph<N: Idx, const BR: bool = false> {
    // a list of targets of outgoing edges and (if enabled) a list of sources of incoming edges.