func (t Tag) IsRoot() bool {
	return compact.Tag(t).IsRoot()
}
IsRoot returns true if t is equal to language "und".
package language
import (
	"strings"
	"golang.org/x/text/internal/language"
	"golang.org/x/text/internal/language/compact"
)
type Tag compact.Tag
func makeTag(t language.Tag) (tag Tag) {
	return Tag(compact.Make(t))
}
func (t *Tag) tag() language.Tag {
	return (*compact.Tag)(t).Tag()
}
func (t *Tag) isCompact() bool {
	return (*compact.Tag)(t).IsCompact()
}
func (t *Tag) lang() language.Language { return t.tag().LangID }
func (t *Tag) region() language.Region { return t.tag().RegionID }
func (t *Tag) script() language.Script { return t.tag().ScriptID }
func Make(s string) Tag {
	return Default.Make(s)
}
func (c CanonType) Make(s string) Tag {
	t, _ := c.Parse(s)
	return t
}
func (t Tag) Raw() (b Base, s Script, r Region) {
	tt := t.tag()
	return Base{tt.LangID}, Script{tt.ScriptID}, Region{tt.RegionID}
}