{"ast_node_type":"other","tokens":[{"end":92,"kind":"keyword","start":0,"text":"///"}]}
    /// then you should take a `TypingEnv` to ensure that you handle opaque types correctly.
    /// you should also probably have a `ParamEnv` from when it was built. If you don't,
    query param_env(def_id: DefId) -> ty::ParamEnv<'tcx> {