code: def boundingRect(self):
      ## boundingRect _must_ indicate the entire area that will be drawn on
      ## or else we will get artifacts and possibly crashing.
      ## (in this case, QPicture does all the work of computing the bouning rect for us)
      return QtCore.QRectF(self.picture.boundingRect())
  
file_path: pyqtgraph/pyqtgraph/examples/customGraphicsItem.py
imports: import pyqtgraph
  from pyqtgraph import QtCore, QtGui
label_desc: Use image node_id 4 for calling the CandlestickItem obj's underlying member method code with example usage: obj.boundingRect() and returns: QtCore