private boolean isNewRowOrType(final ExtendedCell previousCell, final ExtendedCell cell) {
    return previousCell == null || previousCell.getTypeByte() != cell.getTypeByte()
      || !CellUtil.matchingRows(previousCell, cell);
  }
Returns True if we have crossed over onto a new row or type
hbase-server/src/main/java/org/apache/hadoop/hbase/replication/regionserver/ReplicationSink.java