val myExtensionMock = mock<MyExtension>()
                val extensionsSchemaMock = mock<ExtensionsSchema> {
                    on { elements }.thenReturn(listOf<ExtensionSchema>(object : ExtensionSchema {
                        override fun getName(): String = "myExtension"
                        override fun getPublicType(): TypeOf<*> = TypeOf.typeOf(MyExtension::class.java)
                    }))

 * The `@DeferredConfigurable` annotation has been removed.
 * The method `isDeferredConfigurable()` was removed from `ExtensionSchema`.
 * `IdeaPlugin.performPostEvaluationActions()` and `EclipsePlugin.performPostEvaluationActions()` have been removed.
 * `The `BroadcastingCollectionEventRegister.getAddAction()` method has been removed with no replacement.