public ClientFactoryBuilder connectTimeoutMillis(long connectTimeoutMillis) {
        checkArgument(connectTimeoutMillis > 0,
                      "connectTimeoutMillis: %s (expected: > 0)", connectTimeoutMillis);
        return channelOption(ChannelOption.CONNECT_TIMEOUT_MILLIS,
                             Ints.saturatedCast(connectTimeoutMillis));
    }
Sets the timeout of a socket connection attempt in milliseconds.
core/src/main/java/com/linecorp/armeria/client/ClientFactoryBuilder.java