'Args:
hs (synapse.server.HomeServer): server'

def __init__(self, hs):

    super(UsernameAvailabilityRestServlet, self).__init__()
    self.hs = hs
    self.registration_handler = hs.get_handlers().registration_handler
    self.ratelimiter = FederationRateLimiter(hs.get_clock(), window_size=2000, sleep_limit=1, sleep_msec=1000, reject_limit=1, concurrent_requests=1)
