code: def test_gh_4511_regression(self):
      # This modification of the differential evolution docstring example
      # uses a custom popsize that had triggered an off-by-one error.
      # Because we do not care about solving the optimization problem in
      # this test, we use maxiter=1 to reduce the testing time.
      bounds = [(-5, 5), (-5, 5)]
      result = differential_evolution(
          rosen, bounds, popsize=1815, maxiter=1
      )
  
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 27 for calling the TestDifferentialEvolutionSolver obj's underlying member method code with example usage: obj.test_gh_4511_regression() without return types