code: @Override
      public final void write(final byte[] b, final int off, final int len) throws IOException {
          file.write(b, off, len);
          counter = counter + len;
      }
docs: Writes <code>len</code> bytes from the specified byte array starting at offset <code>off</code> to the file.
  
  @param b
  the data.
  @param off
  the start offset in the data.
  @param len
  the number of bytes to write.
  
  @exception IOException
  If an I/O error occurs.