Function draft 

pub fn draft(
    part: &mut NamedModel,
    namer: &Namer,
    faces: &[FaceId],
    neutral: &Plane,
    angle: Scalar,
) -> GeopResult<SolidId>

Tilts the planar faces faces of one solid by angle (in radians, a quarter turn either way at most) about where each meets the plane neutral, whose normal is the pull direction — see the module docs — and returns the drafted solid, which replaces it and is named namer’s root. Every face, edge and vertex keeps its name.