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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 user_exists(self, username):
 """ Returns whether a user with username ``username`` exists. :param str username: username of user :return: whether a user with the specified username exists :rtype: bool :raises NetworkFailure: if there is an error communicating with the server :return: """

        path = "/users/{}".format(username)
        return self._get(path).ok