private static PermissionSupplier userPermissions() {
      try {
        UserPrincipal user =
            FileSystems.getDefault()
                .getUserPrincipalLookupService()
                .lookupPrincipalByName(getUsername());
        ImmutableList<AclEntry> acl =
            ImmutableList.of(
                AclEntry.newBuilder()
                    .setType(ALLOW)
                    .setPrincipal(user)