class ResourceConverterProviderImpl implements ResourceConverterProvider {

    public ToServerConverter<? super ClientResource, ? extends Resource, ToServerConversionOptions> getToServerConverter(String serverType, String clientType){
        prepareConverters();
        return (ToServerConverter<? super ClientResource, ? extends Resource, ToServerConversionOptions>) resourceConverters.get(getCombinedConverterKey(serverType, clientType));
    }

}