getRowId

This optional function is used to derive a unique ID for any given row. If not provided the rows index is used (nested rows join together with . using their grandparents' index eg. index.index.index). If you need to identify individual rows that are originating from any server-side operations, it's suggested you use this function to return an ID that makes sense regardless of network IO/ambiguity eg. a userId, taskId, database ID field, etc.