{
    "base":{
        "outer":[
            "appid",
            "xwho",
            "xwhat",
            "xwhen",
            "xcontext"
        ],
        "xcontext":[
            "$lib",
            "$lib_version",
            "$platform",
            "$debug",
            "$is_login",
            "$device_id"
        ]
    },
    "$app_crash":{
        "xcontext":[
            "$network",
            "$os_version",
            "$is_first_day",
            "$model",
            "$os",
            "$screen_width",
            "$channel",
            "$carrier_name",
            "$brand",
            "$screen_height",
            "$language",
            "$app_version",
            "$is_time_calibrated",
            "$time_zone",
            "$manufacturer",
            "$session_id",
            "$crash_name",
            "$crash_reason",
            "$crash_data"
        ]
    },
    "$startup":{
        "xcontext":[
            "$is_first_time",
            "$is_from_background",
            "$channel",
            "$time_zone",
            "$manufacturer",
            "$app_version",
            "$model",
            "$os",
            "$os_version",
            "$network",
            "$carrier_name",
            "$screen_width",
            "$screen_height",
            "$brand",
            "$language",
            "$is_first_day",
            "$session_id",
            "$is_time_calibrated",
            "$start_source"
        ]
    },
    "$end":{
        "xcontext":[
            "$duration",
            "$channel",
            "$time_zone",
            "$manufacturer",
            "$app_version",
            "$model",
            "$os",
            "$os_version",
            "$network",
            "$carrier_name",
            "$screen_width",
            "$screen_height",
            "$brand",
            "$language",
            "$is_first_day",
            "$session_id",
            "$is_time_calibrated"
        ]
    },
    "$track":{
        "xcontext":[
            "$channel",
            "$time_zone",
            "$manufacturer",
            "$app_version",
            "$model",
            "$os",
            "$os_version",
            "$network",
            "$carrier_name",
            "$screen_width",
            "$screen_height",
            "$brand",
            "$language",
            "$is_first_day",
            "$session_id",
            "$is_time_calibrated"
        ]
    },
    "$pageview":{
        "xcontext":[
            "$title",
            "$url",
            "$channel",
            "$time_zone",
            "$manufacturer",
            "$app_version",
            "$model",
            "$os",
            "$os_version",
            "$network",
            "$carrier_name",
            "$screen_width",
            "$screen_height",
            "$brand",
            "$language",
            "$is_first_day",
            "$session_id",
            "$is_time_calibrated"
        ]
    },
    "$alias":{
        "xcontext":[
            "$idfa",
            "$idfv"
        ]
    },
    "$profile_set_xxx":{
        "xcontext":[
            "$idfa",
            "$idfv"
        ]
    },
    "$first_installation":{
        "xcontext":[
            "$channel",
            "$time_zone",
            "$manufacturer",
            "$app_version",
            "$model",
            "$os",
            "$os_version",
            "$network",
            "$carrier_name",
            "$screen_width",
            "$screen_height",
            "$brand",
            "$language",
            "$is_first_day",
            "$session_id",
            "$is_time_calibrated"
        ]
    }
}
