"operations on them have been supplied.");

  if ((ops->filesystem_ops->new_writable_file != nullptr ||
       ops->filesystem_ops->new_appendable_file != nullptr) &&
      ops->writable_file_ops == nullptr)
    return errors::FailedPrecondition(
        "Filesystem allows creation of writable files but no "
        "operations on them have been supplied.");

  EXPECT_PRED2(UnimplementedOrReturnsCode, status, Code::OUT_OF_RANGE);
}

// The URI schemes that need to be tested are provided by the user via flags
// (or, if none is supplied, all existing schemes are used). As a scheme can
// become available after a shared object with a filesystem implementation is
// loaded, we can only check for availability after all arguments have been
// parsed.
//