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New features:
* Much more sensible reprs for strategies, especially ones that come from
hypothesis.strategies. These should now have as reprs python code that
would produce the same strategy.
* lists() accepts a unique_by argument which forces the generated lists to be
only contain elements unique according to some function key (which must
return a hashable value).
* Better error messages from flaky tests to help you debug things.
Mostly invisible implementation details that may result in finding new bugs
in your code:
* Sets and dictionary generation should now produce a better range of results.
* floats with bounds now focus more on 'critical values', trying to produce
values at edge cases.
* flatmap should now have better simplification for complicated cases, as well
as generally being (I hope) more reliable.
Bug fixes:
* You could not previously use assume() if you were using the forking executor.