text: from queue import Queue
  import pytest
  
  new_queue = Queue()
  
  
  def test_size():
      """Validating if the size is increaseing with queues"""
      assert new_queue._size == 0
      new_queue.enqueue('emma')
      assert new_queue._size == 1
  
  
  def test_enqueue():
      """Validing if the appended value was added to the back of the Queue"""
      new_queue.enqueue('jim')
      assert new_queue.head.val == 'jim'
      new_queue.head._next.val == 'emma'
  
  
  def test_dequque_before():
      """Removing the front node of the Queue"""
      assert new_queue.dequeue() == 'emma'
      assert new_queue._size == 1
  
  def test_dequque_after():
      """Validating if front node was removed and didn't have the same value"""
      assert new_queue.dequeue() != 'emma'
      assert new_queue._size == 0
  
  def test_dequque_error():
      nq = Queue()
      with pytest.raises(IndexError):
          nq.dequeue()
  