presto-main/src/main/java/io/prestosql/execution/resourcegroups/InternalResourceGroup.java/InternalResourceGroup/getQueuedQueries
class InternalResourceGroup:    @Managed
    public int getQueuedQueries()
    {
        synchronized (root) {
            return queuedQueries.size() + descendantQueuedQueries;
        }
    }