Function fetch_operations 

pub async fn fetch_operations<F, Op, D, Error, HistoricalProof, HistoricalFuture, Pins, PinsFuture>(
    op_count: Location<F>,
    start_loc: Location<F>,
    max_ops: NonZeroU64,
    include_pinned_nodes: bool,
    historical_proof: HistoricalProof,
    pinned_nodes_at: Pins,
) -> Result<FetchResult<F, Op, D>, Error>
where
    F: Family,
    D: Digest,
    HistoricalProof: FnOnce(Location<F>, Location<F>, NonZeroU64) -> HistoricalFuture,
    HistoricalFuture: Future<Output = Result<(Proof<F, D>, Vec<Op>), Error>>,
    Pins: FnOnce(Location<F>) -> PinsFuture,
    PinsFuture: Future<Output = Result<Vec<D>, Error>>,

Fetch an operation range from separate local-store callbacks and package it as a FetchResult.

Use this for database APIs that expose historical_proof separately from pinned_nodes_at; pinned nodes are fetched only when include_pinned_nodes is true.