presto-main/src/main/java/io/prestosql/execution/SqlTaskManager.java/SqlTaskManager/getTaskInstanceId
class SqlTaskManager:    @Override
    public String getTaskInstanceId(TaskId taskId)
    {
        SqlTask sqlTask = tasks.getUnchecked(taskId);
        sqlTask.recordHeartbeat();
        return sqlTask.getTaskInstanceId();
    }