code: def test_add():
      queue = Queue()
  
      assert len(queue) == 0
      assert queue.empty
  
      queue.add(1)
      assert len(queue) == 1
  
      queue.add(1)
      assert len(queue) == 2
  
      queue.add(2)
      assert len(queue) == 3
  
imports: import pytest
  from bayes_opt.bayesian_optimization import Queue
label_desc: Use image node_id 1 for calling a global function with example usage: test_add() without return types