The mapping relationship between Checkpoint subtask id and Task subtask id

[杨东晓]

Hi, I'm trying to figure out the different end2end duration for each
subtask id in checkpoint.
In flink web ui I noticed  for job task subtask id it start from 0 and for
checkpoint  subtask id it start from number 1,.
How can I find out which checkpoint subtask id belongs to which job task
subtask id, just simply use checkpoint subtask ID -1 will be ok?
Thanks