@formatjs/intl-datetimeformat/src/get_internal_slots.js

Intl.DateTimeFormat polyfill

// Type-only circular import
// eslint-disable-next-line import/no-cycle
import "@formatjs/ecma402-abstract";
const internalSlotMap = new WeakMap();
export default function getInternalSlots(x) {
	let internalSlots = internalSlotMap.get(x);
	if (!internalSlots) {
		internalSlots = Object.create(null);
		internalSlotMap.set(x, internalSlots);
	}
	return internalSlots;
}