three.js/src/core/Layers.d.ts

export class Layers {

	constructor();

	/**
	 * @default 1 | 0
	 */
	mask: number;

	set( channel: number ): void;
	enable( channel: number ): void;
	enableAll(): void;
	toggle( channel: number ): void;
	disable( channel: number ): void;
	disableAll(): void;
	test( layers: Layers ): boolean;

}