Examine source code of Save Pinned Tabs

{
  "manifest_version": 2,
  "name": "Save Pinned Tabs",
  "short_name": "Save Pinned",
  "version": "1.1.3",
  "browser_specific_settings": {
    "gecko": {
      "id": "savepinnedtabs@buildyourweb.app",
      "strict_min_version": "57.0"
    }
  },
  "description": "Save your current pinned tabs.",
  "icons": {
    "32": "images/icon_32.png",
    "64": "images/icon_64.png",
    "128": "images/icon_128.png"
  },
  "permissions": [
    "tabs",
    "storage"
  ],
  "browser_action": {
    "default_icon": {
      "32": "images/icon_32.png",
      "64": "images/icon_64.png",
      "128": "images/icon_128.png"
    },
    "default_popup": "popup.html",
    "default_title": "Save pinned tabs"
  },
  "background": {
    "scripts": [
      "lib/browser-polyfill.js",
      "functions.js",
      "background.js"
    ],
    "persistent": false
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true,
    "chrome_style": true,
    "open_in_tab": true
  }
}