code: def add_heading(lw, name):
      global num_bars
      lw.addLabel("=== " + name + " ===")
      num_bars += 1
      lw.nextRow()
  
imports: import numpy
  import pyqtgraph
  from pyqtgraph.Qt import QtCore, QtGui, QtWidgets
label_desc: Use image node_id 1 for calling a global function with example usage: add_heading(lw, name) without return types