def register_signal_handler(self, signal_name, handler_function):
self.bus.add_signal_receiver(signal_wrapper(handler_function),<EOL>signal_name=signal_name,<EOL>dbus_interface=self.IFACE,<EOL>bus_name=self.name,<EOL>path=self.OBJ_PATH)<EOL>
register `handler_function` to receive `signal_name`.

        Uses class's dbus interface self.IFACE, objects name self.name
        and objects path self.OBJ_PATH to match signal.

        :param str signal_name: The signal name;
                                None(default) matches all names.
        :param function handler_function: The function to be called.