code: public AbstractButton addButton(final String text, final boolean toggleButton) {
          return addButton(text, (Icon) null, toggleButton);
      }
docs: Adds a button to the {@link ComboButton}.
  
  @param text
  the text of the button
  @param toggleButton
  whether or not this button should be a toggle button (true) or
  a regular button (false)
  @return