_updateCartItem(oBundle, oProductToBeAdded, oCartModel) {
			// find existing entry for product
			const oCollectionEntries = {...oCartModel.getData()["cartEntries"]};
			let oCartEntry =  oCollectionEntries[oProductToBeAdded.ProductId];

			if (oCartEntry === undefined) {
				// create new entry
				oCartEntry = {...oProductToBeAdded};
				oCartEntry.Quantity = 1;
				oCollectionEntries[oProductToBeAdded.ProductId] = oCartEntry;
			} else {
				// update existing entry
				oCartEntry.Quantity += 1;
			}
			//update the cart model
			oCartModel.setProperty("/cartEntries", {...oCollectionEntries});
			oCartModel.refresh(true);
			MessageToast.show(oBundle.getText("productMsgAddedToCart", [oProductToBeAdded.Name]));
		}
Function that updates the cart model when a product is added to the cart.
If the product is already in the cart the quantity is increased.
If not, the product is added to the cart with quantity 1.
@param {Object} oBundle i18n bundle
@param {Object} oProductToBeAdded Product that is added to the cart
@param {Object} oCartModel Cart model