def test_push():
queue = Queue()
queue.push(1)
assert queue.front() == 1
assert queue.size == 1
queue.push(2)
assert queue.front() == 1
assert queue.size == 2
def test_front():
queue = Queue()
queue.push(1)
assert queue.front() == 1
assert queue.size == 1
queue.push(2)
queue.push(3)
assert queue.front() == 1
assert queue.size == 3
for i in range(4, 100):
queue.push(i)
assert queue.front() == 1
def test_pop():
queue = Queue()
queue.push(1)
assert queue.pop() == 1
assert queue.size == 0
queue.push(2)
assert queue.front() == 2
assert queue.size == 1
queue.push(3)
queue.push(4)
assert queue.pop() == 2
assert queue.size == 2
assert queue.pop() == 3
assert queue.pop() == 4
assert queue.size == 0
