Python3 asyncio example: double TCP adding server

adding_server.py

import asyncio

class Server:

    def __init__(self, loop):
        self.loop = loop
        self.counter = 0
        self.server_add = None
        self.server_result = None

    def set_up(self):
        coro_add = asyncio.start_server(self.handle_add, '127.0.0.1', 8888, loop=self.loop)
        self.server_add = self.loop.run_until_complete(coro_add)

        coro_result = asyncio.start_server(self.handle_result, '127.0.0.1', 9999, loop=self.loop)
        self.server_result = self.loop.run_until_complete(coro_result)

    def tear_down(self):
        self.server_result.close()
        self.loop.run_until_complete(self.server_result.wait_closed())

        self.server_add.close()
        self.loop.run_until_complete(self.server_add.wait_closed())

    @asyncio.coroutine
    def handle_add(self, reader, writer):
        writer.close()

        while not reader.at_eof():
            data = yield from reader.readline()
            message = data.decode().strip()
            try:
                self.counter += int(message)
            except ValueError:
                pass

    @asyncio.coroutine
    def handle_result(self, reader, writer):
        writer.write(str(self.counter).encode())
        yield from writer.drain()
        writer.close()

if __name__ == '__main__':
    loop = asyncio.get_event_loop()
    server = Server(loop)
    server.set_up()
    try:
        loop.run_forever()
    except KeyboardInterrupt:
        pass
    server.tear_down()
    loop.close()