public ClassicHttpResponse execute(final ClassicHttpRequest request) throws IOException, HttpException {
        return impl.execute(
                ClassicRequestBuilder.copy(request).build(),
                new ExecChain.Scope("test", route, request, mockExecRuntime, context),
                mockExecChain);
    }
This class tests behavior that is allowed (MAY) by the HTTP/1.1 protocol
specification and for which we have implemented the behavior in HTTP cache.
httpclient5-cache/src/test/java/org/apache/hc/client5/http/impl/cache/TestProtocolAllowedBehavior.java