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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 object_hook(self, object_dict):
 """ Hook which when passed into a json.JSONDecoder will replace each dict in a json string with its index and convert the dict to an object as defined by the passed in condition_decoder. The newly created condition object is appended to the conditions_list. Args: object_dict: Dict representing an object. Returns: An index which will be used as the placeholder in the condition_structure """

    instance = self.decoder(object_dict)
    self.condition_list.append(instance)
    self.index += 1
    return self.index