• window is the length of time window in seconds.
• mode is reserved for future, not used for now.
• evnetN is boolean expression like eventID = 1004.

The function works according to the algorithm:

• The function searches for data that triggers the first condition in the chain and sets the event counter to 1. This is the moment when the sliding window starts.
• If the data has multiple event chains at varying points of completion, the function will only output the size of the longest chain.