docstr: Return a this item's parent in the scenegraph hierarchy.
code: def parentItem(self):
      """Return a this item's parent in the scenegraph hierarchy."""
      return self.__parent
  
imports: from OpenGL.GL import *
  from OpenGL import GL
  from ..None import Transform3D
  from ..Qt import QtCore
label_desc: Use image node_id 5 for calling the GLGraphicsItem obj's underlying member method code with example usage: obj.parentItem() and returns: self