PendingSwapOf: StorageDescriptor<
    FixedSizeArray<2, number>,
    {
        deadline: number;
        desired_collection: number;
        desired_item?: number;
        price?: {
            amount: bigint;
            direction: Enum<{ Receive: undefined; Send: undefined }>;
        };
    },
    true,
    never,
>

Handles all the pending swaps.