The following legal notice applies to all files in this project, unless
explicitly stated otherwise:

    SPDX-License-Identifier: MPL-2.0

    Copyright 2019, the Helvetia contributors.

    This Source Code Form is subject to the terms of the Mozilla Public
    License, v. 2.0. If a copy of the MPL was not distributed with this file,
    You can obtain one at https://mozilla.org/MPL/2.0/.