+ /**
+ * Get the size of the queue.
+ *
+ * @returns The size of the queue.
+ * @readonly
+ */
+ public get size (): number {
+ return this.tail - this.head
+ }
+
+ /**
+ * Enqueue an item.
+ *
+ * @param item - Item to enqueue.
+ * @returns The new size of the queue.
+ */
+ public enqueue (item: T): number {