text: exports.externals = () => ({
      externals: {
          commonjs: 'd3',
          amd: 'd3',
          root: 'd3'
      },
  });
  
  // Loaders
  exports.cssLoader = () => ({
      module: {
          rules: [
              {
                  test: /\.css$/,
                  use: [
                      'style-loader',
                      'css-loader',
                  ]
              },
          ],
      },
  });
  exports.ESLintLoader = () => ({
      module: {
          rules: [
              {
                  enforce: 'pre',
                  test: /\.js$/,
                  include: /src/,
                  exclude: /node_modules/,
                  use: ['eslint-loader'],
              }
          ]
      }
  });
  exports.istanbulLoader = () => ({
      module: {
          rules: [
              {
                  test: /\.js?$/,
                  include: /src/,
                  exclude: /(node_modules|tests.webpack.js)/,
                  use: [{
                      loader: 'istanbul-instrumenter-loader',
                      query: {
                          esModules: true
                      }
                  }],
              }
          ]
      }
  });
  exports.babelLoader = () => ({
      module: {
          rules: [
              {
                  test: /\.js$/,
                  exclude: /node_modules/,
                  use: ['babel-loader'],
              },
          ],
      },
  });