@After
  public void tearDown() throws Exception {
    if (c != null) {
      c.close();
      c = null;
    }
    if (ds != null) {
      ds.disconnect();
      ds = null;
    }
  }
Unit test for basic CacheListener feature. NOTE: these tests using a loner DistributedSystem and
local scope regions so all the listener features tested are for local listeners being invoked for
local operations.

@since GemFire 5.0
geode-core/src/integrationTest/java/org/apache/geode/cache/CacheListenerJUnitTest.java