code: def test_optimizer_built():
      new_optimizer = optimizer.Optimizer()
  
      assert new_optimizer.built is False
  
file_path: opytimizer/tests/opytimizer/core/test_optimizer.py
imports: import sys
  import numpy
  from opytimizer.core import function, optimizer
  from opytimizer.spaces import search
label_desc: Use image node_id 5 for calling a global function with example usage: test_optimizer_built() without return types