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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_auto_field_name(self, model_class):
 """ If one of the unique_fields is the model's AutoField, return the field name, otherwise return None """

        # Get auto field name (a model can only have one AutoField)
        for field in model_class._meta.fields:
            if isinstance(field, AutoField):
                return field.column

        return None