def METHOD_NAME(self, obj):
    rows = CreditCalculationService.get_all(
        model_name="PetroleumCarbonIntensity",
        category_id=obj.id
    )
    serialized = []
    for row in rows:
        serialized.append({
            "fuel_class": obj.name,
            "density": row.density,
            "effective_date": row.effective_date,
            "expiration_date": row.effective_date,
            "create_timestamp": row.create_timestamp
        })
    return serialized