code: func parseHealthConfig(rest string, d *Directive) (*Node, map[string]bool, error) {
  	// Find end of first argument
  	var sep int
  	for ; sep < len(rest); sep++ {
  		if unicode.IsSpace(rune(rest[sep])) {
  			break
  		}
  	}
  	next := sep
  	for ; next < len(rest); next++ {
  		if !unicode.IsSpace(rune(rest[next])) {
  			break
  		}
  	}
  
  	if sep == 0 {
  		return nil, nil, nil
  	}
  
  	typ := rest[:sep]
  	cmd, attrs, err := parseMaybeJSON(rest[next:], d)
  	if err != nil {
  		return nil, nil, err
  	}
  
  	return &Node{Value: typ, Next: cmd}, attrs, err
  }
docs: // The HEALTHCHECK command is like parseMaybeJSON, but has an extra type argument.