@UnstableApi
    public ClientFactoryBuilder useHttp2WithoutAlpn(boolean useHttp2WithoutAlpn) {
        option(ClientFactoryOptions.USE_HTTP2_WITHOUT_ALPN, useHttp2WithoutAlpn);
        return this;
    }
Sets whether to use HTTP/2 without ALPN. This is useful if you want to communicate with an HTTP/2
server over TLS but the server does not support ALPN.
core/src/main/java/com/linecorp/armeria/client/ClientFactoryBuilder.java