Sets the icon for this item to the inputed icon.
        
        :param      icon | <str> || <QIcon> || None

def setIcon(self, icon):
        """
        Sets the icon for this item to the inputed icon.
        
        :param      icon | <str> || <QIcon> || None
        """
        if icon:
            self._icon = QIcon(icon)
        else:
            self._icon = None