func Empty() *Set {
	return &Set{intervalset.Empty()}
}
Empty returns a new, empty Set.
package timespanset
import (
	"fmt"
	"time"
	"github.com/google/go-intervals/intervalset"
)
type Set struct {
	iset *intervalset.Set
}
func (s *Set) String() string {
	return s.iset.String()
}