public void setBufferedIO(boolean bufferedIO) {
    this.bufferedIO = bufferedIO;
    if (bufferedIO) {
      immediateFlush = false;
    }
  }
The <b>BufferedIO</b> option takes a boolean value. It is set to <code>false</code> by default.
If true, then <code>File</code> will be opened and the resulting {@link java.io.Writer} wrapped
around a {@link BufferedWriter}. BufferedIO will significatnly increase performance on heavily
loaded systems.
hbase-logging/src/test/java/org/apache/log4j/FileAppender.java