code: func Raise(max uint64) (uint64, error) {
  	// Get the current limit
  	var limit syscall.Rlimit
  	if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &limit); err != nil {
  		return 0, err
  	}
  	// Try to update the limit to the max allowance
  	limit.Cur = limit.Max
  	if limit.Cur > int64(max) {
  		limit.Cur = int64(max)
  	}
  	if err := syscall.Setrlimit(syscall.RLIMIT_NOFILE, &limit); err != nil {
  		return 0, err
  	}
  	if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &limit); err != nil {
  		return 0, err
  	}
  	return uint64(limit.Cur), nil
  }
docs: // This file is largely identical to fdlimit_unix.go,
  // but Rlimit fields have type int64 on FreeBSD so it needs
  // an extra conversion.
  // Raise tries to maximize the file descriptor allowance of this process
  // to the maximum hard-limit allowed by the OS.