code: func checkIfRuleExists(listChainOutput string, args ...string) bool {
  	rule := strings.Join(args, " ")
  	for _, line := range strings.Split(listChainOutput, "\n") {
  		if strings.TrimSpace(line) == rule {
  			return true
  		}
  	}
  	return false
  }
docs: // checkIfRuleExists takes the output of ebtables list chain and checks if the input rules exists
  // WARNING: checkIfRuleExists expects the input args matches the format and sequence of ebtables list output