// synctestGroupInterface is the methods of synctestGroup used by Server and Transport.
// It's defined as an interface here to let us keep synctestGroup entirely test-only
// and not a part of non-test builds.
type http2synctestGroupInterface interface {
	Join()
	Now() time.Time
	NewTimer(d time.Duration) http2timer
	AfterFunc(d time.Duration, f func()) http2timer