CollectionConfigOf: StorageDescriptor<
    [Key: number],
    {
        max_supply?: number;
        mint_settings: {
            default_item_settings: bigint;
            end_block?: number;
            mint_type: Enum<
                { HolderOf: number; Issuer: undefined; Public: undefined },
            >;
            price?: bigint;
            start_block?: number;
        };
        settings: bigint;
    },
    true,
    never,
>

Config of a collection.