pub fn build_graph(
fragments: &[Fragment],
edges: FxHashMap<(FragmentId, FragmentId), f64>,
categories: FxHashMap<(FragmentId, FragmentId), EdgeCategory>,
) -> GraphExpand description
Map-based adapter kept for tests and small callers; converts to the
compact representation and delegates. Edges whose endpoints are not
in fragments are dropped (the hashmap path silently dropped them
at CSR construction).