Acknowledgements:
backport-util-concurrent is based in large part on the public
domain sources from:
    1) JSR166,
    2) package dl.util.concurrent,
    3) Doug Lea's "collections" package.

This software is released to the public domain
( http://creativecommons.org/licenses/publicdomain )
in the spirit of the original code written by Doug Lea.
The code can be used for any purpose, modified, and redistributed
without acknowledgment. No warranty is provided, either express or implied.

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