Suggestion: provide a maxWait param for cases where flush isn't enough

[klayhb]

So, I was using this code (and thank you for making it) to convert a read Kafka stream into batches (to reduce concurrent load on the downstream destination) -

The issue is that it seems like some ReadableStreams don't actually ever invoke flush, making the strictMode irrelevant
as a replacement, i added a "maxWait" parameter that records the timestamp of the last update, and upon receiving a put into the BatchStream, checks whether the required batch size has been reached OR the maxWait has elapsed since the last put.

This way, there is an occasional internal "flushing" of the stream without waiting for an externally invoked flush...

wdyt?

[roccomuso]

Can you paste code that replicate the issue?