def generated(prefix: str) -> str:
    """Return a header line indicating that this is a generated file."""
    return """{prefix} Copyright 2019 The Fuchsia Authors. All rights reserved.
{prefix} Use of this source code is governed by a BSD-style license that can be
{prefix} found in the LICENSE file.
{prefix} Generated by {generator}.
""".format(
        prefix=prefix,
        generator='//src/tests/fidl/dangerous_identifiers/generate')