如何扩展蓝图中的通用子生成器？

// generators/custom-component/index.js
const Generator = require('yeoman-generator');

module.exports = class extends Generator {
  writing() {
    this.fs.copyTpl(
      this.templatePath('component.js'),
      this.destinationPath('src/components/CustomComponent.js'),
      { name: this.props.name }
    );
  }

  prompting() {
    return this.prompt([
      {
        type: 'input',
        name: 'name',
        message: 'Your component name:',
        default: 'CustomComponent'
      }
    ]).then(props => {
      this.props = props;
    });
  }
};

// generators/app/index.js
const Generator = require('yeoman-generator');

module.exports = class extends Generator {
  constructor(args, opts) {
    super(args, opts);
    this.option('skip-install');
  }

  initializing() {
    this.composeWith(require.resolve('../custom-component'));
  }
};

yo webapp --skip-install