private boolean oplogFileIsInDir(int oplogFileIndex, File dir) {
    String[] files = dir.list();
    String pattern = "BACKUP" + DISK_STORE_NAME + "_" + oplogFileIndex;
    for (String file : files) {
      if (file.contains(pattern)) {
        return true;
      }
    }
    return false;
  }
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