@Override
        public void postAppend(final long size, final long elapsedTime, final WALKey logkey,
          final WALEdit logEdit) {
          appendMeter.mark(size);
        }
Verify the content of the WAL file. Verify that the file has expected number of edits.
@param wals may not be null
@return Count of edits.
hbase-diagnostics/src/main/java/org/apache/hadoop/hbase/wal/WALPerformanceEvaluation.java