Pages: StorageDescriptor<[Enum<{
    Here: undefined;
    Parent: undefined;
    Sibling: number;
    Snowbridge: FixedSizeBinary<32>;
}>, number], {
    first: number;
    first_index: number;
    heap: Binary;
    last: number;
    remaining: number;
    remaining_size: number;
}, true>

The map of page indices to pages.