input: Write a function to open a web browser with a given URL as an argument. If the URL is not provided, default to "http://www.example.com". Return the result of the webbrowser.open function call.
  assert open_webpage("www.google.com")==True
  assert open_webpage("http://www.yahoo.com")==True
  assert open_webpage("www.openai.com")==True
  assert open_webpage("")==True
  assert open_webpage()==True
output: def open_webpage(url="http://www.example.com"):
      import webbrowser
      return webbrowser.open(url)