Output from Window not getting materialized

[Gaurav Nakum]

Hi everyone!

We are developing a new IO connector using the SDF API, and testing it with the 
following simple counting pipeline:
 
p.apply(MyIO.read()
        .withStream(inputStream)
        .withStreamPartitions(Arrays.asList(0))
        .withConsumerConfig(config)
    ) // gets a PCollection<KV<String, String>>
 
 
.apply(Values.<String>create()) // PCollection<String>
 
.apply(Window.<String>into(FixedWindows.of(Duration.standardSeconds(10)))
    .withAllowedLateness(Duration.standardDays(1))
    .accumulatingFiredPanes())
 
.apply(Count.<String>perElement()) 
 
 
// write PCollection<KV<String, Long>> to stream
.apply(MyIO.write()
        .withStream(outputStream)
        .withConsumerConfig(config));
 
 

Without the window transform, we can read from the stream and write to it, 
however, I don’t see output after the Window transform. Could you please help 
pin down the issue?

Thank you,

Gaurav