three.js/examples/jsm/nodes/core/NodeCache.js

let id = 0;

class NodeCache {

	constructor() {

		this.id = id ++;
		this.nodesData = new WeakMap();

	}

	getNodeData( node ) {

		return this.nodesData.get( node );

	}

	setNodeData( node, data ) {

		this.nodesData.set( node, data );

	}

}

export default NodeCache;