code: function createServer(opts) {
    opts.webpackConfigPath = path.resolve(process.cwd(), opts.webpackConfigPath);
    if (fs.existsSync(opts.webpackConfigPath)) {
      opts.webpackConfig = require(path.resolve(process.cwd(), opts.webpackConfigPath));
    } else {
      throw new Error('Must specify webpackConfigPath or create ./webpack.config.js');
    }
    delete opts.webpackConfigPath;
  
    const server = new Server(opts);
    return server;
  }
docs: Create a server instance using the provided options.
  @param  {Object} opts react-native-webpack-server options
  @return {Server}      react-native-webpack-server server