if (componentMetadata != null) {
            AttributeContainerInternal attributes = (AttributeContainerInternal) componentMetadata.getAttributes();
            boolean matching = attributesSchema.matcher().isMatching(attributes, consumerAttributes);
            if (!matching) {
                return new RejectedByAttributesVersion(id, attributesSchema.matcher().describeMatching(attributes, consumerAttributes));
            }
        }

        attributeMatcher.matches(_ as Collection, typeAttributes("classes"), _ as AttributeMatchingExplanationBuilder) >> [variant1, variant2]
        attributeMatcher.isMatching(_, _, _) >> true

        when:
        def result = variantSelectorFactory.create(dependenciesResolverFactory).select(set, typeAttributes("classes"), false, factory)
        visit(result)

        then:

            AttributeValue<?> producerValue = candidateAttributes.findEntry(attributeName);

            if (consumerValue.isPresent() && producerValue.isPresent()) {
                if (attributeMatcher.isMatching(untyped, producerValue.coerce(attribute), consumerValue.coerce(attribute))) {
                    compatible.add(new AssessedAttribute<>(attribute, Cast.uncheckedCast(consumerValue.get()), Cast.uncheckedCast(producerValue.get())));

        if (!consumerAttributes.isEmpty() && !conf.getAttributes().isEmpty()) {
            // Need to validate that the selected configuration still matches the consumer attributes
            if (!attributeMatcher.isMatching(conf.getAttributes(), consumerAttributes)) {
                throw failureHandler.incompatibleRequestedConfigurationFailure(consumerSchema, attributeMatcher, consumerAttributes, targetComponent, conf);
            }
        }

            if (dispatching) {
                // Safety check: dispatching a message should not cause the thread to dispatch another message (eg should not do any logging)
                throw new IllegalStateException("This thread is already dispatching a message.");
            }
            dispatching = true;
            try {
                delegate.dispatch(message);
                delegate.flush();
            } finally {

 * However, the implementations:
 * <ul>
 * <li>should allow separate threads for dispatching and receiving, i.e. single thread that dispatches
 * and a different single thread that receives should be perfectly safe</li>
 * <li>should allow stopping or requesting stopping from a different thread than receiving/dispatching</li>
 * <li>don't guarantee allowing multiple threads dispatching</li>
 * </ul>
 */

		return nil
	}

	// Report differences in environment variables.
	var missing []string
	var mismatching []string
	for k, v := range s1.MinioEnv {
		ev, ok := s2.MinioEnv[k]
		if !ok {
			missing = append(missing, k)
		} else if v != ev {
			mismatching = append(mismatching, k)
		}
	}
	var extra []string
	for k := range s2.MinioEnv {
		_, ok := s1.MinioEnv[k]
		if !ok {

		//   be dispatched, we are not dispatching any other request until
		//   we accumulate enough seats to dispatch the nominated one, even
		//   if currently unoccupied seats would allow for dispatching some
		//   other requests in the meantime
		// As a consequence of these, the wider the request, the more capacity
		// will effectively be blocked and unused during dispatching and
		// executing this request.
		//

          protected Queue<Event> initialValue() {
            return Queues.newArrayDeque();
          }
        };

    /** Per-thread dispatch state, used to avoid reentrant event dispatching. */
    private final ThreadLocal<Boolean> dispatching =
        new ThreadLocal<Boolean>() {
          @Override
          protected Boolean initialValue() {
            return false;
          }
        };

    @Override

          protected Queue<Event> initialValue() {
            return Queues.newArrayDeque();
          }
        };

    /** Per-thread dispatch state, used to avoid reentrant event dispatching. */
    private final ThreadLocal<Boolean> dispatching =
        new ThreadLocal<Boolean>() {
          @Override
          protected Boolean initialValue() {
            return false;
          }
        };

    @Override