class_docstr: Class used to allow GraphicsWidgets to anchor to a specific position on their
  parent. The item will be automatically repositioned if the parent is resized. 
  This is used, for example, to anchor a LegendItem to a corner of its parent 
  PlotItem.
code: def __geometryChanged(self):
      if self.__parent is None:
          return
      if self.__itemAnchor is None:
          return
  
      o = self.mapToParent(Point(0, 0))
      a = self.boundingRect().bottomRight() * Point(self.__itemAnchor)
      a = self.mapToParent(a)
      p = self.__parent.boundingRect().bottomRight() * Point(
          self.__parentAnchor
      )
      off = Point(self.__offset)
      pos = p + (o - a) + off
      self.setPos(pos)
  
imports: from ..Point import Point
label_desc: Use image node_id 4 for calling the GraphicsWidgetAnchor obj's underlying member method code with example usage: obj.__geometryChanged() without return types