Function is_near_netelement_edge 

pub fn is_near_netelement_edge(
    projected_point: &Point<f64>,
    netelement_geometry: &LineString<f64>,
    edge_zone_distance: f64,
) -> bool

Check whether a candidate’s projected point is near a netelement endpoint.

Computes the haversine distance from the projected point to the nearest geometric endpoint of the netelement. If that distance is within edge_zone_distance meters, the candidate is “near the edge” and may transition to an adjacent netelement.

Used as an optimization: candidates that are well inside a netelement (far from both endpoints) cannot plausibly transition to a different netelement, so Dijkstra routing can be skipped for them.