code: function installPackage(packageInstallFolder, name, version) {
      try {
          console.log(`Installing ${name}...`);
          const npmPath = getNpmPath();
          const result = childProcess.spawnSync(npmPath, ['install'], {
              stdio: 'inherit',
              cwd: packageInstallFolder,
              env: process.env
          });
          if (result.status !== 0) {
              throw new Error('"npm install" encountered an error');
          }
          console.log(`Successfully installed ${name}@${version}`);
      }
      catch (e) {
          throw new Error(`Unable to install package: ${e}`);
      }
  }
docs: Run "npm install" in the package install folder.