@Override
  protected void printUsage() {
    StringBuilder footerBuilder = new StringBuilder();
    footerBuilder.append("For performance, consider the following configuration properties:\n");
    footerBuilder.append("-Dhbase.client.scanner.caching=100\n");
    footerBuilder.append("-Dmapreduce.map.speculative=false\n");
    printUsage("hbase rowcounter <tablename> [options] [<column1> <column2>...]", "Options:",
      footerBuilder.toString());
  }
Sets filter {@link FilterBase} to the {@link Scan} instance. If provided rowRangeList contains
more than one element, method sets filter which is instance of {@link MultiRowRangeFilter}. If
rowRangeList contains exactly one element, startRow and stopRow are set to the scan. Also,
method may apply {@link FirstKeyOnlyFilter} an {@link KeyOnlyFilter} for better performance.
hbase-mapreduce/src/main/java/org/apache/hadoop/hbase/mapreduce/RowCounter.java