return null // The domain is a public suffix.
    }

    val firstLabelOffset =
      if (rule[0][0] == EXCEPTION_MARKER) {
        // Exception rules hold the effective TLD plus one.
        domainLabels.size - rule.size
      } else {
        // Otherwise the rule is for a public suffix, so we must take one more label.
        domainLabels.size - (rule.size + 1)
      }

	// must strictly be a subset.
	if d >= nRegionGroups {
		return b&m != 0
	}
	return b&^m == 0
}

var errNoTLD = errors.New("language: region is not a valid ccTLD")

// TLD returns the country code top-level domain (ccTLD). UK is returned for GB.
// In all other cases it returns either the region itself or an error.
//
// This method may return an error for a region for which there exists a

// when not empty.
//
// tls.Config.ServerName (non-empty, set to "example.com") takes
// precedence over "some-other-host.tld" which previously incorrectly
// took precedence. We don't actually connect to (or even resolve)
// "some-other-host.tld", though, because of the Transport.Dial hook.
//
// The httptest.Server has a cert with "example.com" as its name.

		{
			name: "wildcard and explicit unknown",
			cfg: []Configer{
				vsArgs{
					Namespace: "default",
					Match:     "*.tld",
					Dest:      "wild.example.com",
					Time:      TimeOlder,
				},
				vsArgs{
					Namespace: "default",
					Match:     "example.tld",
					Dest:      "explicit.example.com",
					Time:      TimeNewer,
				},
			},
			proxy:     proxy("default"),

			{"http://other.test", ""},
			{"http://test", ""},
		},
	},
	{
		"Host cookie on TLD.",
		"http://com",
		[]string{"a=1"},
		"a=1",
		[]query{
			{"http://com", "a=1"},
			{"http://any.com", ""},
			{"http://any.test", ""},
		},
	},
	{
		"Domain cookie on TLD becomes a host cookie.",
		"http://com",
		[]string{"a=1; domain=com"},
		"a=1",
		[]query{

					return hostLookupCgo, dnsConf
				}
				continue
			case hostname != "" && stringslite.HasPrefix(src.source, "mdns"):
				if stringsHasSuffixFold(hostname, ".local") {
					// Per RFC 6762, the ".local" TLD is special. And
					// because Go's native resolver doesn't do mDNS or
					// similar local resolution mechanisms, assume that
					// libc might (via Avahi, etc) and use cgo.
					return hostLookupCgo, dnsConf
				}

}

// repoRootForImportDynamic finds a *RepoRoot for a custom domain that's not
// statically known by repoRootFromVCSPaths.
//
// This handles custom import paths like "name.tld/pkg/foo" or just "name.tld".
func repoRootForImportDynamic(importPath string, mod ModuleMode, security web.SecurityMode) (*RepoRoot, error) {
	url, err := urlForImportPath(importPath)
	if err != nil {
		return nil, err
	}

	// if ProxyFromEnvironment already executed before our test with empty
	// HTTP_PROXY it will make these tests return false positive failures
	req, err := http.NewRequest("GET", "http://host.fake.tld/", nil)
	if err != nil {
		t.Fatalf("unexpected err: %v", err)
	}
	proxy, err := http.ProxyFromEnvironment(req)
	if err != nil {
		t.Fatalf("unexpected err: %v", err)
	}
	if proxy == nil {

	}{
		{r: strings.NewReader("hello")},
		{r: bytes.NewReader([]byte("hello"))},
		{r: bytes.NewBuffer([]byte("hello"))},
	}
	for i, tt := range tests {
		req, err := NewRequest("POST", "http://foo.tld/", tt.r)
		if err != nil {
			t.Errorf("test[%d]: %v", i, err)
			continue
		}
		if req.Body == nil {
			t.Errorf("test[%d]: Body = nil", i)
			continue
		}
		if req.GetBody == nil {