How to create a sprite by "new" operator?

Phaser 3
1

Hello, I want to inherit from the Phaser.GameObjects.Sprite class, but I find that if I use “new” operator to create the object, nothing will be displayed on the canvas and the displayList property of the sprite is null.

let slime = new Phaser.GameObjects.Sprite(this, 100, 100, "slime_normal");
//Nothing is shown on canvas, and the displayList of slime is null
console.log(slime);

So If I simply extend the Phaser.GameObjects.Sprite, nothing will be shown. How to set the displayList property and inherit from the Sprite class ?

2

Maybe I should add this ?

//"this" is a scene object
this.add.existing(slime);

I find that the sprite shows if I add this line.