How to share the same dependency Injection Tree with tsrynge?

I'd like to have only one instance of each class per child container.

import "reflect-metadata";
import {injectable, container, singleton} from "tsyringe";

const count = {
    bar: 0,
    foo: 0,
    fao: 0
}

@injectable()
class Foo {
    constructor() {
        count.foo += 1;

    }

    public helloWorld() {
        console.log("helloworld")
    }
}

@injectable()
export class Bar {
    constructor(public myFoo: Foo) {
        count.bar += 1;
    }


}

@injectable()
export class FAO {
    constructor(public myFoo: Foo) {
        count.fao += 1;
    }
}

const create = () => {
    const childContainer = container.createChildContainer();
    const myBar = childContainer.resolve(FAO);
    const other = childContainer.resolve(Bar);
}

create();
create();

I d like to have a "singleton" within my childcontainer. All classes would be instanciated only once per child container. @singleton is resolved only within global container.

How can I do this?

There is a method registerSingleton within a child container

const childContainer= container.createChildContainer();
childContainer.registerSingleton(Foo);

childContainer.resolve(Bar)