Can you provide an example for type checking JSX childrens?

type Avatar: () => JSX.Element;
interface ILoginProps {
    accounts: object;
    setFormType: Function;
    children: Avatar;
}
class Login extends React.Component<ILoginProps, ILoginState> {
    public static propTypes = {
        Avatar: React.PropTypes.func,
 }
public render(): JSX.Element {

 const { Avatar } = this.props
 return (<Avatar/>)
}