Is `IN` filter supported in the latest DatastoreInputReader?

[xiaolong]

I've only used equality filters, like:

filters = [("event_type", "=", event_type),
               ("date", ">=", date_start),
               ("date", "<", date_end)]

Is there any plan to add support for the IN filter, as in ("event_type", "IN", list_of_event_types) ? Or is this already possible?