private ProxyType translateProxyType(HttpProxy proxy) {
        switch(proxy.getProxyType()) {
            case HTTP:
                return ProxyType.HTTP;
            case SOCKS4:
                return ProxyType.SOCKS4;
            case SOCKS5:
                return ProxyType.SOCKS5;
            default:
                throw new IllegalStateException("Unexpected value: " + proxy.getProxyType());
        }
    }
Resolve a proxy, if there is one.

@param resourceUri the URI that will be assessed against the proxy configuration
@return the proxy, if there is an appropriate one configured, and it is not on the non-proxy list.
gateway/platforms/vertx3/vertx3/src/main/java/io/apiman/gateway/platforms/vertx3/engine/proxy/SysPropsProxySelector.java