code: function isPackageAlreadyInstalled(packageInstallFolder) {
      try {
          const flagFilePath = path.join(packageInstallFolder, INSTALLED_FLAG_FILENAME);
          if (!fs.existsSync(flagFilePath)) {
              return false;
          }
          const fileContents = fs.readFileSync(flagFilePath).toString();
          return fileContents.trim() === process.version;
      }
      catch (e) {
          return false;
      }
  }
docs: Detects if the package in the specified directory is installed