/** * Query Passio's UPC web service for nutrition attributes of a given barcode. * @param barcode - The barcode value for the attributes query, typically taken from a scanned `BarcodeCandidate`. * @returns A `Promise` resolving to a `PassioFoodItem` object if the record exists in the database or `null` if not. */fetchAttributesForBarcode(barcode: Barcode): Promise<oFoodItem |null>