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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def is_active(feature):
 """ Check if a feature is active """


  if current_app:
    feature_flagger = current_app.extensions.get(EXTENSION_NAME)
    if feature_flagger:
      return feature_flagger.check(feature)
    else:
      raise AssertionError("Oops. This application doesn't have the Flask-FeatureFlag extention installed.")

  else:
    log.warn(u"Got a request to check for {feature} but we're running outside the request context. Check your setup. Returning False".format(feature=feature))
    return False