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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 download_file(self, file_path, range=None):
 """ Download a file from Telegram servers """

        headers = {"range": range} if range else None
        url = "{0}/file/bot{1}/{2}".format(API_URL, self.api_token, file_path)
        return self.session.get(
            url, headers=headers, proxy=self.proxy, proxy_auth=self.proxy_auth
        )