}).
						FromMatch(
							// TODO(JimmyCYJ): enable VM for all test cases.
							util.SourceMatcher(ns, true)).
						ConditionallyTo(echotest.ReachableDestinations).
						ToMatch(util.DestMatcher(ns, true)).
						Run(func(t framework.TestContext, from echo.Instance, to echo.Target) {
							opts := echo.CallOptions{
								To: to,
								Port: echo.Port{
									Name: "http",
								},
							}

	})

	if !skipVM {
		m = match.Or(m, match.ServiceName(echo.NamespacedName{
			Name:      VMSvc,
			Namespace: ns,
		}))
	}

	return m
}

// DestMatcher matches workload pod B with sidecar injected and VM
func DestMatcher(ns namespace.Instance, skipVM bool) match.Matcher {
	m := match.ServiceName(echo.NamespacedName{
		Name:      BSvc,
		Namespace: ns,
	})

	if !skipVM {

						}).
						FromMatch(
							// TODO(JimmyCYJ): enable VM for all test cases.
							util.SourceMatcher(ns, true)).
						ConditionallyTo(echotest.ReachableDestinations).
						ToMatch(util.DestMatcher(ns, true)).
						Run(func(t framework.TestContext, from echo.Instance, to echo.Target) {
							opts := echo.CallOptions{
								To: to,
								Port: echo.Port{
									Name: "http",
								},
							}

)

// only used for testing, exposes a blocking Update method that allows test environments to trigger meshConfig updates
type TestWatcher struct {
	internalWatcher
	doneCh chan struct{} // used to implement a blocking Update method
}

func NewTestWatcher(meshConfig *meshconfig.MeshConfig) *TestWatcher {
	w := &TestWatcher{
		internalWatcher: internalWatcher{},
	}
	w.internalWatcher.MeshConfig.Store(meshConfig)

			ok := true
			if err := a.verify("", regexp.MatchString); err != nil {
				ok = false
			}
			if ok {
				t.Errorf("%s: expected error in any of %q", tc.pattern, a)
			}
		}
	}
}

func TestMatcher(t *T) {
	testCases := []struct {
		pattern     string
		skip        string
		parent, sub string
		ok          bool
		partial     bool
	}{
		// Behavior without subtests.