void clearProgress() {
    progress.setFields(0, 0, 0, getBlockSizeProgress());
  }
Clear away any progress that has been made so far. All progress fields are reset to initial
values. Only clears progress that should reset between rows. {@link #getBlockSizeProgress()} is
not reset because it increments for all blocks scanned whether the result is included or
filtered.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/ScannerContext.java