data *persistencespb.VersioningData,
req *workflowservice.UpdateWorkerVersioningRulesRequest_DeleteBuildIdAssignmentRule,
data = cloneOrMkData(data)
rules := data.GetAssignmentRules()
hadFullyRamped := containsFullyRamped(rules)
idx := req.GetRuleIndex()
actualIdx := given2ActualIdx(idx, rules)
if actualIdx < 0 || actualIdx > len(rules)-1 {
return nil, errAssignmentRuleIndexOutOfBounds(int(idx), len(getActiveAssignmentRules(rules)))
}