Examine source code of Random time theme

{
  "description": "Change the theme according to the user time.",
  "homepage_url": "https://github.com/Chandramouli-CM",
  "icons": {
    "48": "icons/icon_1.png",
    "64": "icons/icon_2.png"
  },
  "manifest_version": 2,
  "name": "Random time theme",
  "permissions": [
    "alarms",
    "theme"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "version": "1.0",
  "applications": {
    "gecko": {
      "strict_min_version": "55.0a2"
    }
  }
}