Queue with Linked List implementation

Queue.swift

public struct Queue<Element> {
    fileprivate let queue = SinglyLinkedList<Element>()
    
    var isEmpty: Bool {
        return queue.isEmpty
    }
    
    var count: Int {
        return queue.count
    }
    
    mutating func enqueue(_ element: Element) {
        queue.append(element)
    }
    
    mutating func dequeue() -> SinglyLinkedListNode<Element>? {
        return queue.remove(node: queue.head!)
    }
    
    func peek() -> SinglyLinkedListNode<Element>? {
        return queue.head!
    }

}