input: Write a function to include a web-page rendering feature by opening a specified URL in the default web browser.
  assert webbrowser_open("www.example.com")==True
  assert webbrowser_open("www.sample.com")==True
  assert webbrowser_open("www.invalid-url.com")==False
  assert webbrowser_open(1234)==False
  assert webbrowser_open("")==False
output: import webbrowser
  
  def webbrowser_open(url):
      if isinstance(url, str) and url.startswith("www."):
          try:
              webbrowser.open(f"http://{url}")
              return True
          except:
              return False
      return False