Upstream Cargo authors (not a substitute for individual copyright notices):
Isis Lovecruft <isis@patternsinthevoid.net>
Henry de Valence <hdevalence@hdevalence.ca>

Retained source/header copyright lines:
// Copyright (c) 2016-2018 Henry de Valence
// Copyright (c) 2016-2018 Isis Lovecruft, Henry de Valence
// Copyright (c) 2016-2019 Henry de Valence
// Copyright (c) 2016-2020 Henry de Valence
// Copyright (c) 2016-2021 isis agora lovecruft
// Copyright (c) 2016-2021 isis lovecruft
// Copyright (c) 2018-2019 Henry de Valence
// Copyright (c) 2019 Henry de Valence.
// Copyright (c) 2019 Oleg Andreev
// Portions Copyright 2017 Brian Smith
