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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 get_branch(self, auth, username, repo_name, branch_name):
 """ Returns the branch with name ``branch_name`` in the repository with name ``repo_name`` owned by the user with username ``username``. :param auth.Authentication auth: authentication object :param str username: username of owner of repository containing the branch :param str repo_name: name of the repository with the branch :param str branch_name: name of the branch to return :return: a branch :rtype: GogsBranch :raises NetworkFailure: if there is an error communicating with the server :raises ApiFailure: if the request cannot be serviced """

        path = "/repos/{u}/{r}/branches/{b}".format(u=username, r=repo_name, b=branch_name)
        response = self.get(path, auth=auth)
        return GogsBranch.from_json(response.json())