@Nullable
    public StandardProtocolFamily ipFamily() {
        if (ipAddr == null) {
            return null;
        }

        return isIpV6(ipAddr) ? StandardProtocolFamily.INET6 : StandardProtocolFamily.INET;
    }
Returns the {@link StandardProtocolFamily} of this endpoint's IP address.

@return the {@link StandardProtocolFamily} of this endpoint's IP address, or
        {@code null} if the host name is not resolved yet.
core/src/main/java/com/linecorp/armeria/client/Endpoint.java