[
  {
    "namespace": "aboutConfigPrefs",
    "description": "experimental API extension to allow access to about:config preferences",
    "events": [
      {
        "name": "onPrefChange",
        "type": "function",
        "parameters": [
          {
            "name": "name",
            "type": "string",
            "description": "The preference which changed"
          }
        ],
        "extraParameters": [
          {
            "name": "name",
            "type": "string",
            "description": "The preference to monitor"
          }
        ]
      }
    ],
    "functions": [
      {
        "name": "getBranch",
        "type": "function",
        "description": "Get all child prefs for a branch",
        "parameters": [
          {
            "name": "branchName",
            "type": "string",
            "description": "The branch name"
          }
        ],
        "async": true
      },
      {
        "name": "getPref",
        "type": "function",
        "description": "Get a preference's value",
        "parameters": [
          {
            "name": "name",
            "type": "string",
            "description": "The preference name"
          }
        ],
        "async": true
      },
      {
        "name": "setPref",
        "type": "function",
        "description": "Set a preference's value",
        "parameters": [
          {
            "name": "name",
            "type": "string",
            "description": "The preference name"
          },
          {
            "name": "value",
            "type": "boolean",
            "description": "The new value"
          }
        ],
        "async": true
      }
    ]
  }
]