presto-main/src/main/java/io/prestosql/execution/resourcegroups/WeightedFairQueue.java/WeightedFairQueue/Usage
class WeightedFairQueue:        public Usage(int share, int utilization)
        {
            checkArgument(share > 0, "share must be positive");
            checkArgument(utilization >= 0, "utilization must be zero or positive");

            this.share = share;
            this.utilization = utilization;
        }