code: function get(scriptModule, agent, msg, cb) {
      const filename = msg.filename;
      if (!filename) {
          cb('empty filename');
          return;
      }
  
      fs.readFile(path.join(scriptModule.root, filename), 'utf-8', (err, data) => {
          if (err) {
              logger.error(`fail to read script file:${filename}, ${err.stack}`);
              cb(`fail to read script with name:${filename}`);
          }
  
          cb(null, data);
      });
  }
docs: Get the content of the script file