public InternalDistributedSystem getSystem() {
    return clientCache.getInternalDistributedSystem();
  }
JUnit Rule that creates ClientCache instances in DistributedTest VMs without
{@code CacheTestCase}.

<p>
{@code ClientCacheRule} can be used in DistributedTests as a {@code Rule}:

<pre>
{@literal @}Rule
public DistributedRule distributedRule = new DistributedRule();

{@literal @}Rule
public ClientCacheRule clientCacheRule = new ClientCacheRule();

{@literal @}Test
public void createClientCache() {
  vm0.invoke(() -&gt; clientCacheRule.createClientCache(new ClientCacheFactory().setPoolRetryAttempts(1));
}
</pre>

<p>
{@link ClientCacheRule.Builder} can also be used to construct an instance with more options:

<pre>
{@literal @}Rule
public DistributedRule distributedRule = new DistributedRule();

{@literal @}Rule
public ClientCacheRule clientCacheRule = ClientCacheRule.builder().createClientCacheInLocal().build();

{@literal @}Test
public void controllerVmCreatedClientCache() {
  assertThat(clientCacheRule.getClientCache()).isNotNull();
}
</pre>
geode-dunit/src/main/java/org/apache/geode/test/dunit/rules/ClientCacheRule.java