UninterruptibleFileChannel testSetCrfChannel(UninterruptibleFileChannel ch) {
    UninterruptibleFileChannel chPrev = crf.channel;
    crf.channel = ch;
    return chPrev;
  }
Method to be used only for testing

@param ch Object to replace the channel in the Oplog.crf
@return original channel object
geode-core/src/main/java/org/apache/geode/internal/cache/Oplog.java