fn derive_cause<'db>(
_interner: DbInterner<'db>,
_candidate_kind: ProbeKind<DbInterner<'db>>,
cause: ObligationCause,
_idx: usize,
_parent_trait_pred: PolyTraitPredicate<'db>,
) -> ObligationCausefn derive_cause<'db>(
_interner: DbInterner<'db>,
_candidate_kind: ProbeKind<DbInterner<'db>>,
cause: ObligationCause,
_idx: usize,
_parent_trait_pred: PolyTraitPredicate<'db>,
) -> ObligationCause