code: func splitHostPortGroupID(raw string) (string, string, error) {
  	s := strings.SplitN(raw, ":", 3)
  	if len(s) != 3 || s[0] != hostPortGroupIDPrefix || s[1] == "" || s[2] == "" {
  		return "", "", fmt.Errorf("corrupt ID: %s", raw)
  	}
  	return s[1], s[2], nil
  }
docs: // splitHostPortGroupID splits a vsphere_host_port_group resource ID into its
  // counterparts: the prefix, the HostSystem ID, and the port group name.