static get type() {

		return 'UserDataNode';

	}
A special type of reference node that allows to link values in
`userData` fields to node objects.
```js
sprite.userData.rotation = 1; // stores individual rotation per sprite

const material = new THREE.SpriteNodeMaterial();
material.rotationNode = userData( 'rotation', 'float' );
```
Since `UserDataNode` is extended from {@link ReferenceNode}, the node value
will automatically be updated when the `rotation` user data field changes.

@augments ReferenceNode