code: function (modelName) {
        if (["make", "list"].indexOf(modelName) === -1) {
          throw new Error(
            "checkOwnerApp middleware can only be configured with 'make' or 'list'. You passed in: '" +
            modelName +
            "'"
          );
        }
  
        return function (req, res, next) {
          // Don't enforce write permissions if not enabled.
          if (!ENFORCE_WRITE_PERMISSIONS) {
            return next();
          }
  
          var model = req[modelName],
            user = req.credentials.user;
          // check if the authenticated application has admin permissions, or if it owns the make
          if (req.credentials.admin !== true && user !== model.ownerApp) {
            return hawkModule.respond(403, res, req.credentials, req.artifacts, {
              status: "failure",
              reason: "unauthorized"
            }, "application/json");
          }
          next();
        };
      }
docs: modelName must be "make" or "list" only