@Override
    public boolean hasUnfinishedResponses() {
        // This method can be called from KeepAliveHandler before HTTP/2 connection receives
        // a settings frame which triggers to initialize responseDecoder.
        // So we just return false because it does not have any unfinished responses.
        if (responseDecoder == null) {
            return false;
        }
        return responseDecoder.hasUnfinishedResponses();
    }
{@code true} if an {@link Http2Settings} has been received from the remote endpoint.
core/src/main/java/com/linecorp/armeria/client/HttpSessionHandler.java