code: def main():
      app = pg.mkQApp()
      loader = ExampleLoader()
      loader.ui.exampleTree.setCurrentIndex(
          loader.ui.exampleTree.model().index(0, 0)
      )
      pg.exec()
  
imports: import keyword
  import os
  import pkgutil
  import re
  import subprocess
  import sys
  from argparse import Namespace
  from collections import OrderedDict
  from functools import lru_cache
  import pyqtgraph
  from pyqtgraph.Qt import QT_LIB, QtCore, QtGui, QtWidgets
  import exampleLoaderTemplate_generic
  import utils
label_desc: Use image node_id 3 for calling a global function with example usage: main() without return types