this.notificationExecutor = checkNotNull(notificationExecutor, "notificationExecutor is null");
this.queryMonitor = checkNotNull(queryMonitor, "queryMonitor is null");
try (SetThreadName ignored = new SetThreadName("Task-%s", taskId)) {
LocalExecutionPlan localExecutionPlan = planner.plan(taskContext.getSession(), fragment.getRoot(), fragment.getSymbols(), new TaskOutputFactory(sharedBuffer));
List<DriverFactory> driverFactories = localExecutionPlan.getDriverFactories();
// index driver factories
DriverSplitRunnerFactory partitionedDriverFactory = null;
ImmutableList.Builder<DriverSplitRunnerFactory> unpartitionedDriverFactories = ImmutableList.builder();