protected Cache createCache() {
    cache = new CacheFactory(props).create();
    ds = cache.getDistributedSystem();
    logWriter = cache.getLogger();
    return cache;
  }
DiskRegionTestingBase: This class is extended to write more JUnit tests for Disk Regions.
<p>
All disk region unit tests extend this base class , common method to be used in all tests are
present here.

@since GemFire 5.1
geode-junit/src/main/java/org/apache/geode/internal/cache/DiskRegionTestingBase.java