code: public static void main(final String[] args) throws TransformerException {
          if (args.length == 2) {
              // using default jpdl 3.2 as XSLT stylesheet.
              transform(args[0], null, args[1]);
          } else if (args.length == 3) {
              // using arg[1] as XSLT stylesheet.
              transform(args[0], args[1], args[2]);
          } else {
              System.err.println("Usage:");
              System.err.println("  java " + JbpmMigration.class.getName() + " jpdlProcessDefinitionFileName xsltFileName outputFileName");
              System.err.println(" or you can use the default jpdl 3.2 transformation:");
              System.err.println("  java " + JbpmMigration.class.getName() + " jpdlProcessDefinitionFileName outputFileName");
              System.exit(1);
          }
      }
docs: Accept two or three command line arguments: - the name of an XML file (required) - the name of an XSLT stylesheet (optional, default is jpdl 3.2) - the
  name of the file the result of the transformation is to be written to.