@Test
  public void create_constructsSystem_withGivenProperties_ifNoSystemExists() {
    InternalCache constructedCache = constructedCache();

    InternalDistributedSystemConstructor systemConstructor = constructorOf(constructedSystem());
    Properties configProperties = new Properties();

    InternalCacheBuilder internalCacheBuilder = new InternalCacheBuilder(
        configProperties, new CacheConfig(), metricsSessionBuilder, THROWING_SYSTEM_SUPPLIER,
        systemConstructor, THROWING_CACHE_SUPPLIER, constructorOf(constructedCache));

    internalCacheBuilder.create();

    verify(systemConstructor).construct(same(configProperties), any(), any());
  }
Unit tests for {@link InternalCacheBuilder} when
{@code InternalDistributedSystem.ALLOW_MULTIPLE_SYSTEMS} is set to true.
geode-core/src/test/java/org/apache/geode/internal/cache/InternalCacheBuilderAllowsMultipleSystemsTest.java