input: Write a function to translate a given text from English to French using the `googletrans` module. If the input text is empty, return an empty string.
  assert translate_text("Hello, this is a sample text to translate.")=="Bonjour, ceci est un texte d'exemple à traduire."
  assert translate_text("Python is awesome!")=="Python est génial !"
  assert translate_text("")==""
output: def translate_text(text):
      if not text:
          return ""
      from googletrans import Translator
      translator = Translator()
      translation = translator.translate(text, src='en', dest='fr')
      return translation.text