Qt.labs.platform SystemTrayIcon activated signal missing reason argument

import QtQuick 2.6
import QtQuick.Window 2.2
import Qt.labs.platform 1.0

Window {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")

    SystemTrayIcon {
        id: _systray
        visible: true
        tooltip: "Hiri"

        onActivated: {
            console.log(reason);
        }

        menu: Menu {
            id: _systrayMenu

            MenuItem {
                text: qsTr("Quit")
                onTriggered: {
                    Qt.quit()
                }
            }
        }
    }
}