docs: def addToGroup(self, item):
          """
          Adds the inputed item to this group.
          
          :param      item | <QtGui.QGraphicsItem>
          """
          effect = QtGui.QGraphicsDropShadowEffect(self.scene())
          effect.setColor(QtGui.QColor('black'))
          effect.setOffset(0, 0)
          effect.setBlurRadius(40)
          item.setGraphicsEffect(effect)
          
          item.setParentItem(self)
          super(XWalkthroughGraphic, self).addToGroup(item)