old_contents: from flask import Flask
  
  app = Flask(__name__)
  
  
  if __name__ == "__main__":
      # Only for debugging while developing
      app.run(host="0.0.0.0", debug=True, port=80)
  
new_contents: from flask import Flask
  
  app = Flask(__name__)
  
  from .core import app_setup
  
  
  if __name__ == "__main__":
      # Only for debugging while developing
      app.run(host="0.0.0.0", debug=True, port=80)
  
subject: Fix missing import in example (#141)