code: func WithLocksExponent(lockExp uint) Option {
  	return func(opts *opts) {
  		opts.poolsize = uint64(1 << lockExp)
  	}
  }
docs: // WithLocksExponent sets the number locks in the lockpool used to lock the time buckets. If the
  // number is greater than the number of buckets, the number of buckets will be used instead.