Copyright (c) The future-queue Contributors

Permission is hereby granted, free of charge, to any
person obtaining a copy of this software and associated
documentation files (the "Software"), to deal in the
Software without restriction, including without
limitation the rights to use, copy, modify, merge,
publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software
is furnished to do so, subject to the following
conditions:

The above copyright notice and this permission notice
shall be included in all copies or substantial portions
of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.

---

The code is derived from futures-rs, and is used under
the Apache 2.0 and MIT licenses.

> Copyright (c) 2016 Alex Crichton
> Copyright (c) 2017 The Tokio Authors
>
> Permission is hereby granted, free of charge, to any
> person obtaining a copy of this software and associated
> documentation files (the "Software"), to deal in the
> Software without restriction, including without
> limitation the rights to use, copy, modify, merge,
> publish, distribute, sublicense, and/or sell copies of
> the Software, and to permit persons to whom the Software
> is furnished to do so, subject to the following
> conditions:
>
> The above copyright notice and this permission notice
> shall be included in all copies or substantial portions
> of the Software.
>
> THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
> ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
> TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
> PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
> SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
> CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
> OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
> IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> DEALINGS IN THE SOFTWARE.
