pub fn parse_bsp_book_deltas(
instrument_id: InstrumentId,
rc: &RunnerChange,
ts_event: UnixNanos,
ts_init: UnixNanos,
) -> Vec<BetfairBspBookDelta>Expand description
Extracts BSP order book deltas from a runner change’s spb/spl fields.
Returns an empty vec when neither spb nor spl data is present.
The side field uses OrderSide::Sell for spb (back) and
OrderSide::Buy for spl (lay), following Betfair’s inverted convention.