code: def test_constraint_solve(self):
      def constr_f(x):
          return np.array([x[0] + x[1]])
  
      nlc = NonlinearConstraint(constr_f, -np.inf, 1.9)
  
      solver = DifferentialEvolutionSolver(
          rosen, [(0, 2), (0, 2)], constraints=(nlc)
      )
  
      # trust-constr warns if the constraint function is linear
      with warns(UserWarning):
          res = solver.solve()
  
      assert constr_f(res.x) <= 1.9
      assert res.success
  
imports: import multiprocessing
  import platform
  from scipy.optimize._differentialevolution import DifferentialEvolutionSolver, _ConstraintWrapper
  from scipy.optimize import differential_evolution
  from scipy.optimize._constraints import Bounds, NonlinearConstraint, LinearConstraint
  from scipy.optimize import rosen
  from scipy.sparse import csr_matrix
  from scipy._lib._pep440 import Version
  import numpy
  from numpy.testing import assert_equal, assert_allclose, assert_almost_equal, assert_array_equal, assert_string_equal, assert_, suppress_warnings
  from pytest import raises, warns
  import pytest
label_desc: Use image node_id 42 for calling the TestDifferentialEvolutionSolver obj's underlying member method code with example usage: obj.test_constraint_solve() and returns: np