code: function finalizeHandler(p, hInfo) {
      if (!p) return;
  
      return p
        .catch(storeErrOnce)
        .then(function () {
          if (errored && !hInfo.ensure) return null;
          _hook(self, 'eachAfter', hInfo, params);
        })
        .catch(storeErrOnce);
    }
docs: Finalize handler exec - should care about errors and post-hooks.