public FSDataInputStream getStream(boolean useHBaseChecksum) {
    return useHBaseChecksum ? this.streamNoFsChecksum : this.stream;
  }
Get the stream to use. Thread-safe.
@param useHBaseChecksum must be the value that shouldUseHBaseChecksum has returned at some
                        point in the past, otherwise the result is undefined.
hbase-server/src/main/java/org/apache/hadoop/hbase/io/FSDataInputStreamWrapper.java