serialize(obj, context) {
		/** @type {string[]} */
		const keys = Object.keys(obj);
		for (const key of keys) {
			context.write(key);
		}
		context.write(null);
		for (const key of keys) {
			context.write(obj[/** @type {keyof T} */ (key)]);
		}
	}
@template {object} T
@param {T} obj null object
@param {ObjectSerializerContext} context context