{"ast_node_type":"import","tokens":[{"end":72,"kind":"keyword","start":0,"text":"///"}]}
/// because `InferOk` is marked with `#[must_use]`, if you have a method
/// around `PredicateObligations<'tcx>`, but it has one important property:
/// `InferCtxt::f` that returns `InferResult<'tcx, ()>` and you call it with