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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_fields(self, view, action_name, resource):
 """ Get fields exposed by action's serializer """

        serializer = view.get_serializer(resource)
        fields = OrderedDict()
        if not isinstance(serializer, view.serializer_class) or action_name == 'update':
            fields = self.get_fields(serializer.fields)
        return fields