docs: public static void main(String[] args) throws IOException {
          if (args.length != 2) {
              System.err.println("Expecting mode(--file/--jar) and path to the file");
          }
  
          String mode = args[0];
          String pathToFile = args[1];
  
          // Check if file exists.
          if (new File(pathToFile).exists()) {
              if (mode.equals("--file")) {
                  instrumentClassFile(pathToFile);
              } else if (mode.equals("--jar")) {
                  instrumentJarFile(pathToFile);
              }
          } else {
              System.err.println("File does not exist: " + pathToFile);
          }
      }