code: def onMouseChanged(self, pointf):
      self.coords = pointf
      self.invalidate()
  
imports: from qtpy import QtWidgets, QtCore
  from qtpy.QtCore import Qt, QPointF
  from qtpy.QtGui import QPen, QColor
label_desc: Use image node_id 11 for calling the AnnotationScene obj's underlying member method code with example usage: obj.onMouseChanged(pointf) without return types