code: func displayProcessTree() {
  	ps := goprocess.FindAll()
  	pstree = make(map[int][]goprocess.P)
  	for _, p := range ps {
  		pstree[p.PPID] = append(pstree[p.PPID], p)
  	}
  	tree := treeprint.New()
  	tree.SetValue("...")
  	seen := map[int]bool{}
  	for _, p := range ps {
  		constructProcessTree(p.PPID, p, seen, tree)
  	}
  	fmt.Println(tree.String())
  }
docs: // displayProcessTree displays a tree of all the running Go processes.