private void closeCache() {
    if (cache != null) {
      region = null;
      Cache c = cache;
      cache = null;
      c.close();
    }
  }
Tests the functionality of the {@link CopyHelper#copy} method and the builtin copy-on-get Cache
functions.

@since GemFire 4.0
geode-core/src/integrationTest/java/org/apache/geode/CopyJUnitTest.java