I`d like to know how I could unit-test the following module.

def download_distribution(url, tempdir):
    """ Method which downloads the distribution from PyPI """
    print "Attempting to download from %s" % (url,)

    try:
        url_handler = urllib2.urlopen(url)
        distribution_contents = url_handler.read()
        url_handler.close()

        filename = get_file_name(url)

        file_handler = open(os.path.join(tempdir, filename), "w")
        file_handler.write(distribution_contents)
        file_handler.close()
        return True

    except ValueError, IOError:
        return False