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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 ping(self, url):
 """Time a single roundtrip to the url. :param url to ping. :returns: the fastest ping time for a given netloc and number of tries. or Pinger.UNREACHABLE if ping times out. :rtype: float Note that we don't use actual ICMP pings, because cmd-line ping is inflexible and platform-dependent, so shelling out to it is annoying, and the ICMP python lib can only be called by the superuser. """

    return self._get_ping_time(url, self._timeout, self._tries)