class {
    onCreate() {
        this.state = {
            toggle: false
        }
    }
    toggle() {
        this.state.toggle = !this.state.toggle;
    }
}

<macro|{ renderBody }| name="content">
    <app-hello key=state.toggle ? "b" : "c"/>
    <${renderBody} key=state.toggle ? "c" : "b"/>
</>

<div key="renderTarget">
    <content>A</>
</div>