@Override
  public final void preTearDownCacheTestCase() throws Exception {
    Error error = null;
    Exception exception = null;

    try {
      preTearDownCompressionRegionOperationsDUnitTest();
    } catch (Error e) {
      error = e;
    } catch (Exception e) {
      exception = e;
    }

    cleanup(getVM(TEST_VM));

    if (error != null) {
      throw error;
    }
    if (exception != null) {
      throw exception;
    }
  }
Populates the put all map and key collection.
geode-core/src/distributedTest/java/org/apache/geode/internal/compression/CompressionRegionOperationsDUnitTest.java