code: func NewMinMaxAllocator(min, max int) (*MinMaxAllocator, error) {
  	if min > max {
  		return nil, ErrInvalidRange
  	}
  	return &MinMaxAllocator{
  		min:  min,
  		max:  max,
  		free: 1 + max - min,
  		used: map[int]bool{},
  	}, nil
  }
docs: // NewMinMaxAllocator return a new allocator or error based on provided min/max value.