@Override
    public int read(long position, byte[] buffer, int offset, int length) throws IOException {
      injectFault();
      return ((PositionedReadable) in).read(position, buffer, offset, length);
    }
Starts to simulate faults on all streams opened so far
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestFSErrorsExposed.java