expect(rtSize).toBe(queue.size)
     expect(queue.head).toBe(0)
     expect(queue.tail).toBe(1)
+    expect(queue.max).toBe(1)
     expect(queue.items).toStrictEqual({ 0: 1 })
     rtSize = queue.enqueue(2)
     expect(queue.size).toBe(2)
     expect(rtSize).toBe(queue.size)
     expect(queue.head).toBe(0)
     expect(queue.tail).toBe(2)
+    expect(queue.max).toBe(2)
     expect(queue.items).toStrictEqual({ 0: 1, 1: 2 })
     rtSize = queue.enqueue(3)
     expect(queue.size).toBe(3)
     expect(rtSize).toBe(queue.size)
     expect(queue.head).toBe(0)
     expect(queue.tail).toBe(3)
+    expect(queue.max).toBe(3)
     expect(queue.items).toStrictEqual({ 0: 1, 1: 2, 2: 3 })
   })