1"track","process","thread","thread_process","ts","dur","category","name"
2"[NULL]","[NULL]","t1","[NULL]",10000,1000,"cat","event1"
3"[NULL]","[NULL]","t1","[NULL]",20000,8000,"cat","event2"
4"[NULL]","[NULL]","t1","[NULL]",21000,7000,"[NULL]","atrace"
5