A callback-style setter may declare the session context of the write as a third parameter (and, for a write to part of an array, the index range as a fourth): context is undefined for a write that does not come from a session.
context
Optional
A callback-style setter may declare the session context of the write as a third parameter (and, for a write to part of an array, the index range as a fourth):
contextis undefined for a write that does not come from a session.