const SettingsManagerInterface = '<interface name="org.freedesktop.DBus.Properties">'+
                                 '<method name="GetAll">'+
                                     '<arg type="s" direction="in"/>'+
                                     '<arg type="a{sv}" direction="out"/>'+
                                 '</method>'+
                                 '<signal name="PropertiesChanged">'+
                                     '<arg type="s,a{sv},a[s]" />' +
                                 '</signal>' +
                                 '</interface>';

let SettingsManagerProxy = Gio.DBusProxy.makeProxyWrapper(SettingsManagerInterface);

const DisplayDeviceInterface = '<interface name="org.freedesktop.UPower.Device">'+
    '<property name="Type" type="u" access="read"/>' +
    '<property name="State" type="u" access="read"/>' +
    '<property name="Percentage" type="d" access="read"/>' +
    '<property name="TimeToEmpty" type="x" access="read"/>' +
    '<property name="TimeToFull" type="x" access="read"/>' +
    '<property name="IsPresent" type="b" access="read"/>' +
    '<property name="IconName" type="s" access="read"/>' +
    '</interface>';