Examine source code of Default Container Cleaner

{
  "manifest_version": 2,
  "name": "Default Container Cleaner",
  "version": "0.1.2resigned1",
  "applications": {
    "gecko": {
      "strict_min_version": "56.0",
      "id": "{3a777f1f-0ad5-41e7-99a4-8c2e6fb1acd6}"
    }
  },
  "description": "This addon will moves all of the tabs in your default container into a new container giving you an easy way to keep your default container clean.",
  "icons": {
    "48": "icons/48.png",
    "96": "icons/96.png"
  },
  "browser_action": {
    "default_icon": "icons/48.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "contextualIdentities",
    "cookies",
    "tabs"
  ]
}