     public var examples: [Example] {
         var examples = childExamples
         for group in childGroups {
-            examples.extend(group.examples)
+            examples.appendContentsOf(group.examples)
         }
         return examples
     }

    internal var afters: [AfterExampleWithMetadataClosure] {
        var closures = hooks.afters
        walkUp() { (group: ExampleGroup) -> () in
            closures.extend(group.hooks.afters)
        }
        return closures
    }

    internal var befores: [BeforeExampleWithMetadataClosure] {
        var closures = Array(hooks.befores.reverse())
        walkUp() { (group: ExampleGroup) -> () in
            closures.appendContentsOf(Array(group.hooks.befores.reverse()))
        }
        return Array(closures.reverse())
    }
