presto-main/src/main/java/io/prestosql/execution/ClusterSizeMonitor.java/ClusterSizeMonitor/ClusterSizeMonitor
class ClusterSizeMonitor:    public ClusterSizeMonitor(
            InternalNodeManager nodeManager,
            boolean includeCoordinator,
            int executionMinCount,
            Duration executionMaxWait)
    {
        this.nodeManager = requireNonNull(nodeManager, "nodeManager is null");
        this.includeCoordinator = includeCoordinator;
        checkArgument(executionMinCount >= 0, "executionMinCount is negative");
        this.executionMinCount = executionMinCount;
        this.executionMaxWait = requireNonNull(executionMaxWait, "executionMaxWait is null");
        this.executor = newSingleThreadScheduledExecutor(threadsNamed("node-monitor-%s"));
    }