webpack4.41.2在引入css时，需要安装css-loader和style-loader，在安装好以后，yarn build仍然报错：
warning " > css-loader@6.7.1" has incorrect peer dependency "webpack@^5.0.0".
warning " > style-loader@3.3.1" has incorrect peer dependency "webpack@^5.0.0".
css-loader@6.7.1" has incorrect peer dependency "webpack@^5.0.0".
css TypeError: this.getOptions is not a function
类似于上面的提示报错，那就可能是loader版本过高，不兼容 getOptions 函数方法，与webpack@4.41.2不兼容的情况，需要把高版本的loader卸载，再安装低版本与webpack@4.41.2匹配的，重新运行：
npm uninstall css-loader //卸载高版本的loader
npm uninstall style-loader //卸载高版本的loader
npm install css-loader@3.2.0 //安装低版本的loader
npm install style-loader@1.0.1 //安装低版本的loader
