code: public FastAdapterDialog<Item> withButton(int whichButton, String text, OnClickListener listener) {
          setButton(whichButton, text, listener);
          return this;
      }
docs: Sets a listener to be invoked when the positive button of the dialog is pressed. This method
  has no effect if called after {@link #show()}.
  
  @param whichButton Which button to set the listener on, can be one of
  {@link DialogInterface#BUTTON_POSITIVE},
  {@link DialogInterface#BUTTON_NEGATIVE}, or
  {@link DialogInterface#BUTTON_NEUTRAL}
  @param text        The text to display in positive button.
  @param listener    The {@link DialogInterface.OnClickListener} to use.