docs: @Override
      public void intializeSubCommand( Subparsers subparsers ) {
          Subparser transformParser = subparsers.addParser( "transform" )
                  .description( "Jolt CLI Transform Tool. This tool will ingest a JSON spec file and an JSON input (from a file or " +
                          "standard input) and run the transforms specified in the spec file on the input. The program will return an " +
                          "exit code of 0 if the input is transformed successfully or a 1 if an error is encountered" )
                  .defaultHelp( true );
  
          File nullFile = null;
          transformParser.addArgument( "spec" ).help( "File path to Jolt Transform Spec to execute on the input. " +
                  "This file should contain valid JSON." )
                  .type( Arguments.fileType().verifyExists().verifyIsFile().verifyCanRead() );
          transformParser.addArgument( "input" ).help( "File path to the input JSON for the Jolt Transform 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( nullFile );   // these last two method calls make input optional
  
          transformParser.addArgument( "-u" ).help( "Turns off pretty print for the output. Output will be raw json with no formatting." )
                  .action( Arguments.storeTrue() );
      }