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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 take_dynamips_id(self, project_id, dynamips_id):
 """ Reserve a dynamips id or raise an error :param project_id: UUID of the project :param dynamips_id: Asked id """

        self._dynamips_ids.setdefault(project_id, set())
        if dynamips_id in self._dynamips_ids[project_id]:
            raise DynamipsError("Dynamips identifier {} is already used by another router".format(dynamips_id))
        self._dynamips_ids[project_id].add(dynamips_id)