code: public static void append(File file, byte[] bytes) throws IOException {
          OutputStream stream = null;
          try {
              stream = new FileOutputStream(file, true);
              stream.write(bytes, 0, bytes.length);
              stream.flush();
  
              OutputStream temp = stream;
              stream = null;
              temp.close();
          } finally {
              closeWithWarning(stream);
          }
      }
docs: Append bytes to the end of a File.  It <strong>will not</strong> be
  interpreted as text.
  
  @param file  a File
  @param bytes the byte array to append to the end of the File
  @throws IOException if an IOException occurs.
  @since 1.5.1