code: def test_differential_evolution(self):
      # test that the Jmin of DifferentialEvolutionSolver
      # is the same as the function evaluation
      solver = DifferentialEvolutionSolver(self.quadratic, [(-2, 2)])
      result = solver.solve()
      assert_almost_equal(result.fun, self.quadratic(result.x))
  
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 14 for calling the TestDifferentialEvolutionSolver obj's underlying member method code with example usage: obj.test_differential_evolution() without return types