code: def test_callback_terminates(self):
      # test that if the callback returns true, then the minimization halts
      bounds = [(0, 2), (0, 2)]
  
      def callback(param, convergence=0.0):
          return True
  
      result = differential_evolution(rosen, bounds, callback=callback)
  
      assert_string_equal(
          result.message,
          "callback function requested stop early " "by returning True",
      )
  
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 16 for calling the TestDifferentialEvolutionSolver obj's underlying member method code with example usage: obj.test_callback_terminates() and returns: True