code: public void reinitialize(InputStream systemIn, PrintStream systemOut, PrintStream systemErr) throws IOException {
          if (reader != null) {
              reader.shutdown();
          }
          initialize(systemIn, systemOut, systemErr);
      }
docs: Use in testing when System.out, System.err or System.in change.
  
  @param systemIn  The system in
  @param systemOut The system out
  @param systemErr The system err
  @throws IOException if there is an error