if (isIvyMetadata(descriptorClass, metadata)) {
            IvyModuleResolveMetadata ivyMetadata = (IvyModuleResolveMetadata) metadata;
            IvyModuleDescriptor descriptor = new DefaultIvyModuleDescriptor(ivyMetadata.getExtraAttributes(), ivyMetadata.getBranch(), ivyMetadata.getStatus());
            return descriptorClass.cast(descriptor);
        } else if (isPomMetadata(descriptorClass, metadata)) {

        if (legacyMetadata instanceof IvyModuleResolveMetadata) {
            IvyModuleResolveMetadata ivyMetadata = (IvyModuleResolveMetadata) legacyMetadata;
            return new DefaultIvyModuleDescriptor(ivyMetadata.getExtraAttributes(), ivyMetadata.getBranch(), ivyMetadata.getStatus());
        }
        return null;
    }

    @Override
    public boolean isUsable() {
        return usable;
    }

        def metadata = ivyMetadata().asImmutable()

        expect:
        processor.processMetadata(metadata).is(metadata)
    }

    def "instantiates class rule when processing metadata"() {
        given:

    }

    def "produces sensible error when rule action throws an exception"() {
        def failure = new Exception("from test")
        def metadata = ivyMetadata()

        when:
        handler.all { throw failure }

        and:
        handler.createComponentMetadataProcessor(context).processMetadata(metadata.asImmutable())

        then:

        if (metadata instanceof IvyModuleResolveMetadata) {
            IvyModuleResolveMetadata ivyMetadata = (IvyModuleResolveMetadata) metadata;
            return new DefaultIvyComponentGraphResolveState(idGenerator.nextComponentId(), ivyMetadata, attributeDesugaring, idGenerator);
        }

            if (legacyMetadata instanceof IvyModuleResolveMetadata) {
                IvyModuleResolveMetadata ivyMetadata = (IvyModuleResolveMetadata) legacyMetadata;
                return new DefaultIvyModuleDescriptor(ivyMetadata.getExtraAttributes(), ivyMetadata.getBranch(), ivyMetadata.getStatus());
            }
        }
        return null;
    }

    private boolean resolve() {

            return fromMavenDescriptor(mavenMetadata.getDependencyDescriptor());
        } else if (originalMetadata instanceof IvyDependencyMetadata) {
            IvyDependencyMetadata ivyMetadata = (IvyDependencyMetadata) originalMetadata;
            return fromIvyDescriptor(ivyMetadata.getDependencyDescriptor());
        } else if (originalMetadata instanceof GradleDependencyMetadata){
            return fromGradleMetadata((GradleDependencyMetadata) originalMetadata);