code: def test_zerospolesgain(self):
      zeros_c = np.array([0.5, -0.5])
      poles_c = np.array([1.0j / np.sqrt(2), -1.0j / np.sqrt(2)])
      k_c = 1.0
  
      zeros_d = [1.23371727305860, 0.735356894461267]
      polls_d = [
          0.938148335039729 + 0.346233593780536j,
          0.938148335039729 - 0.346233593780536j,
      ]
      k_d = 1.0
  
      dt_requested = 0.5
  
      zeros, poles, k, dt = c2d(
          (zeros_c, poles_c, k_c), dt_requested, method="zoh"
      )
  
      assert_array_almost_equal(zeros_d, zeros)
      assert_array_almost_equal(polls_d, poles)
      assert_almost_equal(k_d, k)
      assert_almost_equal(dt_requested, dt)
  
imports: import numpy
  from numpy.testing import assert_array_almost_equal, assert_almost_equal, assert_allclose, assert_equal
  import pytest
  from scipy.signal import cont2discrete
  from scipy.signal import dlsim, ss2tf, ss2zpk, lsim2, lti
  from scipy.signal import tf2ss, impulse2, dimpulse, step2, dstep
label_desc: Use image node_id 9 for calling the TestC2D obj's underlying member method code with example usage: obj.test_zerospolesgain() without return types