function getHeaders$5(headers) {
	let kind = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 'key+value';

	const keys = Object.keys(headers[MAP$5]).sort();
	return keys.map(kind === 'key' ? function (k) {
		return k.toLowerCase();
	} : kind === 'value' ? function (k) {
		return headers[MAP$5][k].join(', ');
	} : function (k) {
		return [k.toLowerCase(), headers[MAP$5][k].join(', ')];
	});
}
Get an iterator on entries.

This is the default iterator of the Headers object.

@return  Iterator