docs: @Override
      public void intializeSubCommand( Subparsers subparsers ) {
          Subparser diffyParser = subparsers.addParser( "diffy" )
                  .description( "Jolt CLI Diffy Tool. This tool will ingest two JSON inputs (from files or standard input) and " +
                          "perform the Jolt Diffy operation to detect any differences. The program will return an exit code of " +
                          "0 if no differences are found or a 1 if a difference is found or an error is encountered." )
                  .defaultHelp( true );
  
          diffyParser.addArgument( "filePath1" ).help( "File path to feed to Input #1 for the Diffy operation. " +
                  "This file should contain valid JSON." )
                  .type( Arguments.fileType().verifyExists().verifyIsFile().verifyCanRead() );
          diffyParser.addArgument( "filePath2" ).help( "File path to feed to Input #2 for the Diffy operation. " +
                  "This file should contain valid JSON. " +
                  "If this argument is not specified then standard input will be used." )
                  .type( Arguments.fileType().verifyExists().verifyIsFile().verifyCanRead() )
                  .nargs( "?" ).setDefault( (File) null );   // these last two method calls make filePath2 optional
  
          diffyParser.addArgument( "-s" ).help( "Diffy will suppress output and run silently." )
                  .action( Arguments.storeTrue() );
          diffyParser.addArgument( "-a" ).help( "Diffy will not consider array order when detecting differences" )
                  .action( Arguments.storeTrue() );
      }