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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 url(self, key):
 """Creates a full URL to the API using urls dict """

        return urlunparse((self.protocol, '%s:%s' % (self.domain, self.port),
                           '%s/api/v1%s' % (self.prefix, URLS[key]),
                           '', '', ''))