{"ast_node_type":"other","tokens":[{"end":50,"kind":"keyword","start":0,"text":"ty::UserType::new_with_bounds("}]}
                    ty::UserType::new_with_bounds(
                let c_ty = self.fcx.infcx.canonicalize_user_type_annotation(
                        ty::UserTypeKind::Ty(o_ty.raw),