Examine source code of Switch Host Extension

{
  "name": "Switch Host Extension",
  "description": "Switch between different hosts quickly.",
  "manifest_version": 2,
  "version": "1.2",
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "58.0",
      "id": "{7bc61e30-1e23-49f1-ab38-8bade07f5381}"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "storage",
    "tabs"
  ],
  "commands": {
    "toggle-feature-cycle-hosts": {
      "suggested_key": {
        "default": "Ctrl+Shift+Y"
      },
      "description": "Cycle through predefined host names"
    }
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  }
}