code: def test_immediate_updating(self):
      # check setting of immediate updating, with default workers
      bounds = [(0.0, 2.0), (0.0, 2.0)]
      solver = DifferentialEvolutionSolver(rosen, bounds)
      assert_(solver._updating == "immediate")
  
      # should raise a UserWarning because the updating='immediate'
      # is being overriden by the workers keyword
      with warns(UserWarning):
          solver = DifferentialEvolutionSolver(rosen, bounds, workers=2)
          assert_(solver._updating == "deferred")
  
imports: import multiprocessing
  from scipy.optimize import _differentialevolution
  from scipy.optimize._differentialevolution import DifferentialEvolutionSolver
  from scipy.optimize import differential_evolution
  import numpy
  from scipy.optimize import rosen
  from numpy.testing import assert_equal, assert_allclose, assert_almost_equal, assert_string_equal, assert_
  from pytest import raises, warns
label_desc: Use image node_id 35 for calling the TestDifferentialEvolutionSolver obj's underlying member method code with example usage: obj.test_immediate_updating() without return types