 	///
 	///		[2, 3, 4, 5].prepend(1) -> [1, 2, 3, 4, 5]
 	///		["e", "l", "l", "o"].prepend("h") -> ["h", "e", "l", "l", "o"]
-	///		// It also works for other types!
 	///
 	/// - Parameter newElement: element to insert.
 	public mutating func prepend(_ newElement: Element) {

	///		[1, 2, 2, 3, 4, 2, 5].lastIndex(of 2) -> 5
	///		[1.2, 2.3, 4.5, 3.4, 4.5].lastIndex(of 6.5) -> nil
	///		["h", "e", "l", "l", "o"].lastIndex(of "l") -> 3
	///		// It also works for other types!
	///
	/// - Parameter item: item to check.
	/// - Returns: last index of item in array (if exists).

	///
	///		[1, 2, 3, 4, 5].pop() // returns 5 and remove it from the array.
	///		[].pop() // returns nil since the array is empty.
	///
	/// - Returns: last element in array (if applicable).
	@discardableResult public mutating func pop() -> Element? {
