Function rings_are_parallels 

pub fn rings_are_parallels(
    model: &Model,
    surface: &SurfaceGeometry,
    rings: &[&Shape],
    tol: Tolerances,
) -> OgeomResult<bool>

Whether two closed ring edges are parallels of surface, so that make_revolution_band can build a band between them. A reader asks this first: a periodic face bounded by two closed circles that are not parallels (a button head’s rims, square to the screw on a sphere whose chart runs along z) is a legitimate face on its own bounds, not a band missing its seam, and deserves no warning.

Errors

OgeomError::Dangling if an edge is not in the model.