old_contents: const common = require("./webpack.config");
  const webpack = require("webpack");
  const UglifyJSPlugin = require("uglifyjs-webpack-plugin");
  
  module.exports = Object.assign(common, {
      mode: 'production',
      plugins: [
          new UglifyJSPlugin({
              sourceMap: true,
              uglifyOptions: { ecma: 8 },
          }),
          new webpack.DefinePlugin({
              "process.env": {
                  NODE_ENV: '"production"',
              },
          }),
      ],
  });
  
new_contents: const common = require("./webpack.config");
  
  module.exports = Object.assign(common, {
      mode: 'production',
  });
  
subject: Remove unused settings