private Http2ConnectionDecoder decoder(Http2Connection connection, Http2ConnectionEncoder encoder) {
        final ArmeriaHttp2HeadersDecoder headersDecoder = new ArmeriaHttp2HeadersDecoder(
                /* validateHeaders */ false, clientFactory.http2MaxHeaderListSize());
        Http2FrameReader reader = new DefaultHttp2FrameReader(headersDecoder);
        reader = new Http2InboundFrameLogger(reader, frameLogger);
        return new DefaultHttp2ConnectionDecoder(connection, encoder, reader);
    }
A handler that closes an HTTP/2 connection when the server responds with an HTTP/1 response, so that
HTTP/1 is used instead of HTTP/2 on next connection attempt.
core/src/main/java/com/linecorp/armeria/client/HttpClientPipelineConfigurator.java