code: func (it *IPTracker) AddStatement(host, endpoint string) {
  	now := it.clock.Now()
  	it.statements[host] = ipStatement{endpoint, now}
  	if time.Duration(now-it.lastStatementGC) >= it.window {
  		it.gcStatements(now)
  	}
  }
docs: // AddStatement records that a certain host thinks our external endpoint is the one given.