'Stop listening for events on ``fd``.'

def remove_handler(self, fd):

    if (fd not in self.handlers):
        return
    if (fd in self.readers):
        self.loop.remove_reader(fd)
        self.readers.remove(fd)
    if (fd in self.writers):
        self.loop.remove_writer(fd)
        self.writers.remove(fd)
    del self.handlers[fd]
