code: def test_parentItem():
      parent = GLGraphicsItem()
      child = GLVolumeItem(None, parentItem=parent)
      ensure_parentItem(parent, child)
  
imports: import pytest
  from pyqtgraph.opengl.GLGraphicsItem import GLGraphicsItem
  from pyqtgraph.opengl import GLVolumeItem
  from common import ensure_parentItem
label_desc: Use image node_id 1 for calling a global function with example usage: test_parentItem() without return types