code: func IsParent(path, parent string) bool {
  	if parent == path {
  		// Twice the same root on windows would not be caught at the end.
  		return false
  	}
  	if filepath.IsAbs(path) != filepath.IsAbs(parent) {
  		return false
  	}
  	if parent == "" || parent == "." {
  		// The empty string is the parent of everything except the empty
  		// string and ".". (Avoids panic in the last step.)
  		return path != "" && path != "."
  	}
  	if parent == "/" {
  		// The root is the parent of everything except itself, which would
  		// not be caught below.
  		return path != "/"
  	}
  	if parent[len(parent)-1] != PathSeparator {
  		parent += string(PathSeparator)
  	}
  	return strings.HasPrefix(path, parent)
  }
docs: // IsParent compares paths purely lexicographically, meaning it returns false
  // if path and parent aren't both absolute or relative.