def __init__(self, worker_id):
super(Service, self).__init__()<EOL>self._initialize(worker_id)<EOL>
Create a new Service

        :param worker_id: the identifier of this service instance
        :type worker_id: int

        The identifier of the worker can be used for workload repartition
        because it's consistent and always the same.

        For example, if the number of workers for this service is 3,
        one will got 0, the second got 1 and the last got 2.
        if worker_id 1 died, the new spawned process will got 1 again.