code: public static Map<String, Double> measureAll(MeterRegistry registry) {
          requireNonNull(registry, "registry");
  
          final ImmutableMap.Builder<String, Double> builder = ImmutableMap.builder();
  
          registry.forEachMeter(meter -> Streams.stream(meter.measure()).forEach(measurement -> {
              final String fullName = measurementName(meter.getId(), measurement);
              final double value = measurement.getValue();
              builder.put(fullName, value);
          }));
  
          return builder.build();
      }
docs: Returns a newly-created immutable {@link Map} which contains all values of {@link Meter}s in the
  specified {@link MeterRegistry}. The format of the key string is:
  <ul>
  <li>{@code <name>#<statistic>{tagName=tagValue,...}}</li>
  <li>e.g. {@code "armeria.server.activeRequests#value{method=greet}"}</li>
  <li>e.g. {@code "someSubsystem.someValue#sumOfSquares"} (no tags)</li>
  </ul>
  Note: It is not recommended to use this method for the purposes other than testing.