我正在努力使我的网站建设更快。我跑了webpack --profile --display-modules并得到了：
$ webpack --profile --display-modules
Hash: 0fa2cca1c766767df763
Version: webpack 4.29.3
Time: 17935ms
Built at: 2019-02-10 07:42:33
Asset Size Chunks Chunk Names
06a1d1de577c6db8255ba0ebc8b4b030.png 234 KiB [emitted]
9d6aca9458d25cec43a3f8331e366585.jpg 21.2 KiB [emitted]
bb03f577e109b6ccd5ba410e76eb780d.jpeg 80.3 KiB [emitted]
fd45fe81dbfbfc6809508c5520e0d1dd.jpeg 1010 KiB [emitted]
index_bundle.js 3.52 MiB main [emitted] main
Entrypoint main = index_bundle.js
[0] multi webpack/hot/dev-server ./static/index.tsx 40 bytes {main} [built]
factory:1ms building:6ms = 7ms
[./node_modules/classnames/index.js] 1.17 KiB {main} [built]
[0] 7ms -> [./static/index.tsx] 13390ms -> [./static/components/App.tsx] 1143ms -> [./static/components/Home.tsx] 2227ms -> factory:2231ms building:34ms dependencies:593ms = 19625ms
[./node_modules/css-loader/index.js!./node_modules/sass-loader/lib/loader.js!./static/components/App.scss] ./node_modules/css-loader!./node_modules/sass-loader/lib/loader.js!./static/components/App.scss 825 bytes {main} [built]
[0] 7ms -> [./static/index.tsx] 13390ms -> [./static/components/App.tsx] 1143ms -> [./static/components/App.scss] 2227ms -> factory:595ms building:1360ms dependencies:0ms = 18722ms
[./node_modules/css-loader/index.js!./node_modules/sass-loader/lib/loader.js!./static/components/BuyPage.scss] ./node_modules/css-loader!./node_modules/sass-loader/lib/loader.js!./static/components/BuyPage.scss 471 bytes {main} [built]
[0] 7ms -> [./static/index.tsx] 13390ms -> [./static/components/App.tsx] 1143ms -> [./static/components/BuyPage.tsx] 2227ms -> [./static/components/BuyPage.scss] 2105ms -> factory:590ms building:1210ms dependencies:1ms = 20673ms
[./node_modules/css-loader/index.js!./node_modules/sass-loader/lib/loader.js!./static/components/Event.scss] ./node_modules/css-loader!./node_modules/sass-loader/lib/loader.js!./static/components/Event.scss 356 bytes {main} [built]
....many similar lines
documentation描述了factory，building和dependency次，但是相对于没有标签的13390ms，这些数字都较小。 13390ms是从哪里来的？我该如何减少呢？