Examine source code of Open Tabs Next to Current

{
  "applications": {
    "gecko": {
      "id": "opentabsnexttocurrent@sblask",
      "strict_min_version": "57.0"
    }
  },
  "author": "Sebastian Blask",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "commands": {
    "open-new-tab-at-default-location": {
      "description": "Open new tab at default location",
      "suggested_key": {
        "default": "Ctrl+Y",
        "windows": "Ctrl+Shift+Y"
      }
    }
  },
  "description": "Open new tabs to the right of the current one.",
  "homepage_url": "https://github.com/sblask/webextension-open-tabs-next-to-current",
  "icons": {
    "48": "icon.svg"
  },
  "manifest_version": 2,
  "name": "Open Tabs Next to Current",
  "permissions": [
    "sessions"
  ],
  "version": "2.0.14"
}