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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 _set_current_context(self, device_id):
 """Sets the number of the currently handled device. Parameters device_id : int The number of current device. """

        if device_id not in self._all_index_update_counts:
            self._all_index_update_counts[device_id] = {}
        self._index_update_count = self._all_index_update_counts[device_id]