code: public FastAdapterDialog<Item> withPositiveButton(String text, OnClickListener listener) {
          return withButton(BUTTON_POSITIVE, text, listener);
      }
docs: Set a listener to be invoked when the positive button of the dialog is pressed.
  
  @param text     The text to display in the positive button
  @param listener The {@link DialogInterface.OnClickListener} to use.
  @return This Builder object to allow for chaining of calls to set methods