Java PushbackInputStream .unread (byte[] b)

public void unread(byte[] b)  throws IOException

//w  w w  . j a va  2  s  .  com
import java.io.*;

public class Main {

   public static void main(String[] args) {
      byte[] arrByte = new byte[1024];
      byte[] byteArray = new byte[]{'j', 'a', 'v', 'a', '2','s','.','c','o','m'};

      InputStream is = new ByteArrayInputStream(byteArray);
      PushbackInputStream pis = new PushbackInputStream(is, 10);

      try {
         for (int i = 0; i < byteArray.length; i++) {
            arrByte[i] = (byte) pis.read();
            System.out.println((char) arrByte[i]);
         }
         byte[] b = {'W', 'o', 'r', 'l', 'd'};
         pis.unread(b);
         for (int i = 0; i < byteArray.length; i++) {
            arrByte[i] = (byte) pis.read();
            System.out.println((char) arrByte[i]);
         }
      } catch (Exception ex) {
         ex.printStackTrace();
      }
   }
}