code: def test__ensure_constraint(self):
      trial = np.array([1.1, -100, 0.9, 2.0, 300.0, -0.00001])
      self.dummy_solver._ensure_constraint(trial)
  
      assert_equal(trial[2], 0.9)
      assert_(np.logical_and(trial >= 0, trial <= 1).all())
  
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 13 for calling the TestDifferentialEvolutionSolver obj's underlying member method code with example usage: obj.test__ensure_constraint() without return types