debugSiblingRefreshSetBuilds property
Cumulative count of O(siblings) sibling-refresh set builds, i.e.
calls to _addSiblingRefreshInto, which both _siblingRefreshSet
and the runBatch exit drain route through. Perf pin for the
deferral contract: K mutations under ONE parent inside one batch
must build the refresh set once, not K times. Counts builds rather
than keys, so the budget is exact and independent of the sibling
count. The increment is assert-guarded, so a release build pays
nothing on a mutation hot path. Never reset internally; tests zero
it directly, the same convention as
debugIndexInParentIterationCount.
Implementation
int debugSiblingRefreshSetBuilds = 0;