docs: def addButton(self, button, role=QDialogButtonBox.ActionRole):
          """
          Adds a custom button to the button box for this popup widget.
          
          :param      button | <QAbstractButton> || <str>
          
          :return     <button> || None (based on if a button or string was given)
          """
          return self._buttonBox.addButton(button, role)