// Node.prototype.contains

(function() {

	function contains(node) {

		if (!(0 in arguments)) {

			throw new TypeError('1 argument is required');

		}

		do {

			if (this === node) {

				return true;

			}

		// eslint-disable-next-line no-cond-assign

		} while (node = node && node.parentNode);

		return false;

	}

	// IE

	if ('HTMLElement' in self && 'contains' in HTMLElement.prototype) {

		try {

			delete HTMLElement.prototype.contains;

		// eslint-disable-next-line no-empty

		} catch (e) {}

	}

	if ('Node' in self) {

		Node.prototype.contains = contains;

	} else {

		document.contains = Element.prototype.contains = contains;

	}

}());