h.WriteString(sa)
		h.Write(Separator)
	}
	h.Write(Separator)

	if t.endpointBuilder != nil {
		t.endpointBuilder.WriteHash(h)
	}

	return h.Sum64()
}

func (t *clusterCache) DependentConfigs() []model.ConfigHash {
	drs := t.destinationRule.GetFrom()
	configs := make([]model.ConfigHash, 0, len(drs)+1+len(t.envoyFilterKeys))
	if t.destinationRule != nil {
		for _, dr := range drs {

					Namespace: "default",
				}.HashCode(),
			},
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got := tt.r.DependentConfigs(); !reflect.DeepEqual(got, tt.want) {
				t.Errorf("DependentConfigs got %v, want %v", got, tt.want)
			}
		})
	}
}

func TestExtractNamespaceForKubernetesService(t *testing.T) {
	tests := []struct {
		hostname string

	// Type indicates the type of Xds resource being cached like CDS.
	Type() string
	// Key is the key to be used in cache.
	Key() any
	// DependentConfigs is config items that this cache key is dependent on.
	// Whenever these configs change, we should invalidate this cache entry.
	DependentConfigs() []ConfigHash
	// Cacheable indicates whether this entry is valid for cache. For example

	}
	ns := hostname[nsI+1 : ih]
	if len(ns) == 0 {
		return "", fmt.Errorf("namespace not found")
	}
	return ns, nil
}

func (r *Cache) DependentConfigs() []model.ConfigHash {
	size := len(r.Services) + len(r.VirtualServices) + len(r.DelegateVirtualServices) + len(r.EnvoyFilterKeys)
	for _, mergedDR := range r.DestinationRules {
		size += len(mergedDR.GetFrom())
	}