Examine source code of MySessions

{
  "description": "A simple session manager. You can quickly save your current browser state and reload it whenever necessary.",
  "manifest_version": 2,
  "name": "MySessions",
  "short_name": "MS",
  "version": "2023.11.2",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "applications": {
    "gecko": {
      "id": "balyaev@gmail.com"
    }
  },
  "icons": {
    "16": "img/icon16.png",
    "48": "img/icon48.png",
    "128": "img/icon128.png"
  },
  "options_ui": {
    "page": "options.html"
  },
  "browser_action": {
    "default_icon": {
      "19": "img/icon19.png",
      "38": "img/icon38.png"
    },
    "default_title": "MySessions",
    "default_popup": "popup.html",
    "theme_icons": [
      {
        "light": "img/icon19-w.png",
        "dark": "img/icon19.png",
        "size": 19
      },
      {
        "light": "img/icon38-w.png",
        "dark": "img/icon38.png",
        "size": 38
      }
    ]
  },
  "permissions": [
    "activeTab",
    "tabs",
    "storage",
    "bookmarks",
    "unlimitedStorage"
  ],
  "optional_permissions": [
    "downloads"
  ],
  "default_locale": "en"
}