Hello! I was reading through the partition code, and I noticed that the criteria for expanding an ISR <https://github.com/apache/kafka/blob/trunk/core/src/main/scala/kafka/cluster/Partition.scala#L926-L958> differs from the criteria to shrink an ISR <https://github.com/apache/kafka/blob/trunk/core/src/main/scala/kafka/cluster/Partition.scala#L1167-L1178> .
Specifically to summarize, I noticed that a replica can be considered as eligible for expansion if its local end offset is >= the leaders high watermark, but is considered "out of sync" if its local end offset != the leaders local end offset. It was a bit surprising to me that the criteria here would be different, is there some part of the picture that I'm missing? Thanks in advance! Zach
