code: def test_imaginary(self):
      # bode() should not fail on a system with pure imaginary poles.
      # The test passes if bode doesn't raise an exception.
      system = TransferFunction([1], [1, 0, 100], dt=0.1)
      dbode(system, n=2)
  
imports: from __future__ import division, print_function, absolute_import
  import numpy
  from numpy.testing import assert_equal, assert_array_almost_equal, assert_array_equal, assert_allclose, assert_, assert_almost_equal
  from pytest import raises
  from scipy._lib._numpy_compat import suppress_warnings
  from scipy.signal import dlsim, dstep, dimpulse, tf2zpk, lti, dlti, StateSpace, TransferFunction, ZerosPolesGain, dfreqresp, dbode, BadCoefficients
label_desc: Use image node_id 5 for calling the Test_bode obj's underlying member method code with example usage: obj.test_imaginary() without return types