return -1, -1, fmt.Errorf("port number %d should be >=0", num)
		}
		if i == 0 {
			beginPort = num
			continue
		}
		endPort = num
		// switch when first port number > second port number
		if beginPort > endPort {
			endPort = beginPort
			beginPort = num
		}
	}
	return beginPort, endPort, nil
}

	testCases := []struct {
		portRange string
		expectErr bool
		beginPort int
		endPort   int
		desc      string
	}{
		{ // case[0]
			portRange: "1-100",
			expectErr: false,
			beginPort: 1,
			endPort:   100,
		},
		{ // case[1]
			portRange: "0-0",
			expectErr: false,
			beginPort: 0,
			endPort:   0,
		},
		{ // case[2]
			portRange: "100-10",

* Code generated for CRDs now passes `go vet`. ([#62412](https://github.com/kubernetes/kubernetes/pull/62412), [@bhcleek](https://github.com/bhcleek))
* "beginPort+offset" format support for port range which affects kube-proxy only ([#58731](https://github.com/kubernetes/kubernetes/pull/58731), [@yue9944882](https://github.com/yue9944882))