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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 image_authn(self):
 """Check to see if user if authenticated for image requests. Must have access cookie with an appropriate value. """

        authn_cookie = request.cookies.get(
            self.access_cookie_name, default='[none]')
        return self.access_cookie_valid(authn_cookie, "image_authn: auth cookie")