private static String scheme(Request req) {
            var scheme = req.getHttpURI().getScheme();
            if (scheme == null) return "none";
            return switch (scheme) {
                case "http", "https" -> scheme;
                default -> "other";
            };
        }
A {@link RequestLog} implementation that collects statistics like HTTP response types aggregated by category.
Implemented as a {@link RequestLog} instead of {@link org.eclipse.jetty.server.handler.EventsHandler} to ensure
that 400 responses from e.g. invalid request headers are also included.

@author ollivir
@author bjorncs
container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/MetricAggregatingRequestLog.java