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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_action_strings(cls, possible_actions: List[List[ProductionRule]], action_indices: Dict[int, List[List[int]]]) -> List[List[List[str]]]: """ Takes a list of possible actions and indices of decoded actions into those possible actions for a batch and returns sequences of action strings. We assume ``action_indices`` is a dict mapping batch indices to k-best decoded sequence lists. """

        all_action_strings: List[List[List[str]]] = []
        batch_size = len(possible_actions)
        for i in range(batch_size):
            batch_actions = possible_actions[i]
            batch_best_sequences = action_indices[i] if i in action_indices else []
            # This will append an empty list to ``all_action_strings`` if ``batch_best_sequences``
            # is empty.
            action_strings = [[batch_actions[rule_id][0] for rule_id in sequence]
                              for sequence in batch_best_sequences]
            all_action_strings.append(action_strings)
        return all_action_strings