code: def test_boolean_return(self):
      # the return must be a bool, else an error will be raised in
      # basinhopping
      ret = self.met(res_new=self.res_new, res_old=self.res_old)
      assert isinstance(ret, bool)
  
imports: import copy
  from numpy.testing import assert_almost_equal, assert_equal, assert_, assert_allclose
  import pytest
  from pytest import raises
  import numpy
  from numpy import cos, sin
  from scipy.optimize import basinhopping, OptimizeResult
  from scipy.optimize._basinhopping import Storage, RandomDisplacement, Metropolis, AdaptiveStepsize
label_desc: Use image node_id 2 for calling the Test_Metropolis obj's underlying member method code with example usage: obj.test_boolean_return() without return types