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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 fetch_url(self, url):
 """ Retrieves the given url to the prefix Args: url(str):
 Url to retrieve Returns: str: path to the downloaded file """

        url_path = urlparse.urlsplit(url).path
        dst_path = os.path.basename(url_path)
        dst_path = self.paths.prefixed(dst_path)
        with LogTask('Downloading %s' % url):
            urllib.urlretrieve(url=os.path.expandvars(url), filename=dst_path)

        return dst_path