Function fillet_edges_checked 

pub fn fillet_edges_checked(
    model: &mut Model,
    solid: &Shape,
    edges: &[Shape],
    radius: f64,
    tol: Tolerances,
) -> Result<Built, BlendRefusal>

fillet_edges, its refusal naming the edges of edges it concerns, by their indices there.

On success the same as fillet_edges. Refused, the indices are read from the request’s check where it refused there: the edge whose ball does not sit on its faces, or the edge whose contact stands in another’s band, then that other. A refusal of the build after the check names the first edge of the request whose prefix of the request does not build (each prefix built on a copy of the model), then, where that edge builds alone, the edges before it sharing a vertex or a face with it.

Errors

As fillet_edges, in a BlendRefusal.