def id1 = new NamespaceId('namespace', 'info1')
        def id2 = new NamespaceId('namespace', 'info2')
        def extraAttrs = [:]
        extraAttrs[id1] = "info1 value"
        extraAttrs[id2] = "info2 value"
        metadata.extraAttributes = extraAttrs
        metadata.branch = "someBranch"

        def capturedDescriptor = null

}


class CompositeFunctionExtractor(internal val extractors: Iterable<FunctionExtractor>) : FunctionExtractor {
    override fun memberFunctions(kClass: KClass<*>, preIndex: DataSchemaBuilder.PreIndex): Iterable<SchemaMemberFunction> =
        extractors.flatMapTo(mutableSetOf()) { it.memberFunctions(kClass, preIndex) }

    ModelRuleExtractor createModelRuleInspector(List<MethodModelRuleExtractor> extractors, ModelSchemaStore modelSchemaStore, StructBindingsStore structBindingsStore, ManagedProxyFactory managedProxyFactory) {
        List<MethodModelRuleExtractor> coreExtractors = MethodModelRuleExtractors.coreExtractors(modelSchemaStore);
        return new ModelRuleExtractor(Iterables.concat(coreExtractors, extractors), managedProxyFactory, modelSchemaStore, structBindingsStore);
    }

        def handle = executer.withTasks("extract").start()
        // Wait for all extracters to be ready
        waiting.waitForAllPendingCalls()

        def firstExtracter = server.expectAndBlock("extract")
        // release the extracters so they start trying to extract concurrently
        waiting.releaseAll()
        // wait for the first extracter to start extracting