presto-main/src/main/java/io/prestosql/execution/executor/TaskExecutor.java/TaskExecutor/RunningSplitInfo
class TaskExecutor:        public RunningSplitInfo(long startTime, String threadId, Thread thread)
        {
            this.startTime = startTime;
            this.threadId = threadId;
            this.thread = thread;
            this.printed = false;
        }