code: def test_KeyError(self):
      # should raise KeyError if kwargs f_old or f_new is not passed
      assert_raises(KeyError, self.met, f_old=1.0)
      assert_raises(KeyError, self.met, f_new=1.0)
  
imports: from __future__ import division, print_function, absolute_import
  import copy
  from numpy.testing import assert_almost_equal, assert_equal, assert_
  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 4 for calling the Test_Metropolis obj's underlying member method code with example usage: obj.test_KeyError() without return types