OCFWriter.Append should return number of bytes written

[nmyk]

Hi! I'm trying to build a data pipeline that writes data to Avro files, and when an individual file reaches a certain size, I want to close it and start a new file. Currently I have to check the file size after every write (records are not fixed-size), but if OCFWriter.appendDataIntoBlock returned the number of bytes written through OCFWriter.Append, I could just add that number to an accumulator instead of making repeated calls to os.File.Stat().

The exact line where the number of bytes written is thrown away is https://github.com/linkedin/goavro/blob/master/ocf_writer.go#L227

Thank you!