t.Errorf("replaceFunc: want %+v but got %+v", c.applied, applied)
			}

			// insertBeforeFunc
			got, applied = insertBeforeFunc(slices.Clone(c.input), f)
			if !slices.Equal(c.insertBefore, got) {
				t.Errorf("insertBeforeFunc: want %+v but got %+v", c.insertBefore, got)
			}
			if c.applied != applied {
				t.Errorf("insertBeforeFunc: want %+v but got %+v", c.applied, applied)
			}

			// insertAfterFunc

		if ok, r := f(v); ok {
			s[k] = r
			applied = true
			break
		}
	}
	return s, applied
}

// insertBeforeFunc find and insert an element before the found element.
// If the f function returns true, the returned value will be inserted before the found element.
func insertBeforeFunc[E any](s []E, f func(e E) (bool, E)) ([]E, bool) {
	var toInsert E
	idx := -1
	for k, v := range s {
		if ok, r := f(v); ok {

				lis.ListenerFilters = append([]*listener.ListenerFilter{proto.Clone(lp.Value).(*listener.ListenerFilter)}, lis.ListenerFilters...)
				continue
			}
			lis.ListenerFilters, applied = insertBeforeFunc(
				lis.ListenerFilters,
				func(e *listener.ListenerFilter) (bool, *listener.ListenerFilter) {
					if listenerFilterMatch(e, lp) {
						return true, proto.Clone(lp.Value).(*listener.ListenerFilter)
					}

			if !hasRouteMatch(rp) {
				virtualHost.Routes = append([]*route.Route{proto.Clone(rp.Value).(*route.Route)}, virtualHost.Routes...)
				continue
			}
			virtualHost.Routes, applied = insertBeforeFunc(
				virtualHost.Routes,
				func(e *route.Route) (bool, *route.Route) {
					if routeMatch(e, rp) {
						return true, proto.Clone(rp.Value).(*route.Route)
					}
					return false, nil
				},
			)