Examine source code of Average Fuel Consumption

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  "icons": {
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    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "http://average-consumption.pekapps.cz/"
  ],
  "browser_action": {
    "default_title": "Average Consumption",
    "default_icon": {
      "19": "icons/icon19.png",
      "38": "icons/icon38.png"
    },
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "@AverageConsumption"
    }
  }
}