Function graph_algo_ptas::algorithm::dualgraph::dual_graph

pub fn dual_graph(
    g: &impl GraphDCEL<LinkVertex, LinkDart, LinkFace, LinkGraphIter<LinkVertex>, LinkGraphIter<LinkDart>, LinkGraphIter<LinkFace>>,
    span: &Span<LinkVertex>
) -> HashMap<LinkFace, HashSet<LinkFace>>

Returns the dual graph that doesn’t cross the edges of the span (face tree)