Downloads a file from the specified URL.

        :param str url: The URL to the file to be downloaded

        :returns: the downloaded file's content
        :rtype: str

def download_file(url):
    """
        Downloads a file from the specified URL.

        :param str url: The URL to the file to be downloaded

        :returns: the downloaded file's content
        :rtype: str
    """
    response = requests.get(url)
    if response.status_code is not 200:
        return None
    return response.text