public Execution createExecution(Chain<COMPONENT> chain, Request processingRequest) {
        int traceLevel = processingRequest.properties().getInteger("tracelevel", 0);
        return Execution.createRoot(chain, traceLevel, new Execution.Environment<>(chainRegistry));
    }
Throws UnsupportedOperationException: Call handle(request, channel instead)
container-core/src/main/java/com/yahoo/processing/handler/AbstractProcessingHandler.java