Package errorsample samples error values uniformly at
random from an unbounded set of inputs.

If you have more errors than you know what to do with,
and you can't read them all or even store them all,
and you want to get a rough idea of what all is going
wrong, this package is for you!

	set := errorsample.New(20)
	...
	set.Add(err) // add errors
	...
	set.Add(err) // LOTS of errors
	...
	errs := make([]error, set.Cap())
	errs = errs[:set.Sample(errs)]
	fmt.Println("20 representative errors:", errs)