@Override
    protected void checkRequiredOptions() throws MissingOptionException {
      if (this.cmd.getArgList().size() < 1 || this.cmd.getArgList().get(0).startsWith("-")) {
        throw new MissingOptionException("First argument must be a valid table name.");
      }
    }
Main entry point.
@param args The command line parameters.
@throws Exception When running the job fails.
hbase-mapreduce/src/main/java/org/apache/hadoop/hbase/mapreduce/RowCounter.java