// Apply quota changes
Quotas quotas = quotaOps.fetch();
quotaOps.preApply(quotas);
Quotas.Builder builder = (quotas != null) ? quotas.toBuilder() : Quotas.newBuilder();
if (req.hasThrottle()) applyThrottle(builder, req.getThrottle());
if (req.hasBypassGlobals()) applyBypassGlobals(builder, req.getBypassGlobals());
// Submit new changes
quotas = builder.build();