import os

class Channel(object):
    def __init__(self, server, name):
        self.server = server
        self.name = name
        self.members = set()

    def add_member(self, client):
        self.members.add(client)

    def remove_client(self, client):
        self.members.discard(client)
        if not self.members:
            self.server.remove_channel(self)