private static void assertSignature(global::Dbus.Signature actual, global::Dbus.Signature expected)
 {
     if (actual != expected)
     {
         throw new System.InvalidOperationException($"Unexpected signature. Got '{actual}', but expected '{expected}'");
     }
 }
 private static void assertSignature(global::Dbus.Signature actual, global::Dbus.Signature expected)
 {
     if (actual != expected)
     {
         throw new global::Dbus.DbusException(
                   global::Dbus.DbusException.CreateErrorName("InvalidSignature"),
                   "Invalid signature"
                   );
     }
 }