WildcardValue        string
	DNSLookupFamilyValue string
)

const (
	LocalhostIPv4       LocalhostValue       = "127.0.0.1"
	LocalhostIPv6       LocalhostValue       = "::1"
	WildcardIPv4        WildcardValue        = "0.0.0.0"
	WildcardIPv6        WildcardValue        = "::"
	DNSLookupFamilyIPv4 DNSLookupFamilyValue = "V4_ONLY"
	DNSLookupFamilyIPv6 DNSLookupFamilyValue = "V6_ONLY"

			option:   option.DNSLookupFamily(option.DNSLookupFamilyIPv4),
			expected: option.DNSLookupFamilyValue("V4_ONLY"),
		},
		{
			testName: "dns lookup family v6",
			key:      "dns_lookup_family",
			option:   option.DNSLookupFamily(option.DNSLookupFamilyIPv6),
			expected: option.DNSLookupFamilyValue("V6_ONLY"),
		},
		{
			testName: "dns lookup family dual stack",
			key:      "dns_lookup_family",