How to use the gbulb.glib_events.GLibHandle function in gbulb

def add_reader(self, fd, callback, *args):
        if not isinstance(fd, int):
            fd = fd.fileno()

        self.remove_reader(fd)

        s = GLib.unix_fd_source_new(fd, GLib.IO_IN)

        assert fd not in self._readers
        self._readers[fd] = GLibHandle(self, s, True, callback, args)

def add_writer(self, fd, callback, *args):
        if not isinstance(fd, int):
            fd = fd.fileno()

        self.remove_writer(fd)

        s = GLib.unix_fd_source_new(fd, GLib.IO_OUT)

        assert fd not in self._writers
        self._writers[fd] = GLibHandle(self, s, True, callback, args)

def call_later(self, delay, callback, *args):

        if delay <= 0:
            return self.call_soon(callback, *args)
        else:
            return GLibHandle(
                self,
                GLib.Timeout(delay*1000 if delay > 0 else 0),
                False,
                callback, args)

def add_signal_handler(self, sig, callback, *args):
        self._check_signal(sig)
        self.remove_signal_handler(sig)

        s = GLib.unix_signal_source_new(sig)
        if s is None:
            if sig == signal.SIGKILL:
                raise RuntimeError("cannot catch SIGKILL")
            else:
                raise ValueError("signal not supported")

        assert sig not in self._sighandlers
        self._sighandlers[sig] = GLibHandle(self, s, True, callback, args)