code: func (h *Handle) RuleAdd(rule *Rule) error {
  	req := h.newNetlinkRequest(unix.RTM_NEWRULE, unix.NLM_F_CREATE|unix.NLM_F_EXCL|unix.NLM_F_ACK)
  	return ruleHandle(rule, req)
  }
docs: // RuleAdd adds a rule to the system.
  // Equivalent to: ip rule add