private void putEntries(Region region, int numToPut) {
    for (int i = 1; i <= numToPut; i++) {
      region.put(i, i);
    }
  }
Returns true if the files of the given oplog file are in the
given directory.
geode-core/src/integrationTest/java/org/apache/geode/internal/cache/DiskStoreImplIntegrationTest.java