code: def test_step_response():
      if not numpy:
          skip("NumPy is required for this test")
  
      def step_res_tester(sys, expected_value):
          x, y = _to_tuple(
              *step_response_numerical_data(sys, adaptive=False, n=10)
          )
          x_check = check_point_accuracy(x, expected_value[0])
          y_check = check_point_accuracy(y, expected_value[1])
          return x_check and y_check
  
      exp1 = (
          (
              0.0,
              1.1111111111111112,
              2.2222222222222223,
              3.3333333333333335,
              4.444444444444445,
              5.555555555555555,
              6.666666666666667,
              7.777777777777779,
              8.88888888888889,
              10.0,
          ),
          (
              -1.9193285738516863e-08,
              0.42283495488246126,
              0.7840485977945262,
              0.5546841805655717,
              0.33903033806932087,
              0.4627251747410237,
              0.5909907598988051,
              0.5247213989553071,
              0.4486997874319281,
              0.4839358435839171,
          ),
      )
      exp2 = (
          (
              0.0,
              1.1111111111111112,
              2.2222222222222223,
              3.3333333333333335,
              4.444444444444445,
              5.555555555555555,
              6.666666666666667,
              7.777777777777779,
              8.88888888888889,
              10.0,
          ),
          (
              0.0,
              0.13728409095645816,
              0.19474559355325086,
              0.1974909129243011,
              0.16841657696573073,
              0.12559777736159378,
              0.08153828016664713,
              0.04360471317348958,
              0.015072994568868221,
              -0.003636420058445484,
          ),
      )
      exp3 = (
          (
              0.0,
              1.1111111111111112,
              2.2222222222222223,
              3.3333333333333335,
              4.444444444444445,
              5.555555555555555,
              6.666666666666667,
              7.777777777777779,
              8.88888888888889,
              10.0,
          ),
          (
              0.0,
              0.6314542141914303,
              2.9356520038101035,
              9.37731009663807,
              28.452300356688376,
              86.25721933273988,
              261.9236645044672,
              795.6435410577224,
              2416.9786984578764,
              7342.154119725917,
          ),
      )
      exp4 = (
          (
              0.0,
              1.1111111111111112,
              2.2222222222222223,
              3.3333333333333335,
              4.444444444444445,
              5.555555555555555,
              6.666666666666667,
              7.777777777777779,
              8.88888888888889,
              10.0,
          ),
          (
              0.0,
              2.286236899862826,
              18.28989519890261,
              61.72839629629631,
              146.31916159122088,
              285.7796124828532,
              493.8271703703705,
              784.1792566529494,
              1170.553292729767,
              1666.6667,
          ),
      )
      exp5 = (
          (
              0.0,
              1.1111111111111112,
              2.2222222222222223,
              3.3333333333333335,
              4.444444444444445,
              5.555555555555555,
              6.666666666666667,
              7.777777777777779,
              8.88888888888889,
              10.0,
          ),
          (
              -3.999999997894577e-09,
              0.6720357068882895,
              0.4429938256137113,
              0.5182010838004518,
              0.4944139147159695,
              0.5016379853883338,
              0.4995466896527733,
              0.5001154784851325,
              0.49997448824584123,
              0.5000039745919259,
          ),
      )
      exp6 = (
          (
              0.0,
              1.1111111111111112,
              2.2222222222222223,
              3.3333333333333335,
              4.444444444444445,
              5.555555555555555,
              6.666666666666667,
              7.777777777777779,
              8.88888888888889,
              10.0,
          ),
          (
              -1.5433688493882158e-09,
              0.3428705539937336,
              1.1253619102202777,
              3.1849962651016517,
              9.47532757182671,
              28.727231099148135,
              87.29426924860557,
              265.2138681048606,
              805.6636260007757,
              2447.387582370878,
          ),
      )
  
      assert step_res_tester(tf1, exp1)
      assert step_res_tester(tf2, exp2)
      assert step_res_tester(tf3, exp3)
      assert step_res_tester(tf4, exp4)
      assert step_res_tester(tf5, exp5)
      assert step_res_tester(ser2, exp6)
  
imports: from math import isclose
  from sympy.core.numbers import I
  from sympy.core.symbol import Dummy
  from sympy.functions.elementary.complexes import Abs, arg
  from sympy.functions.elementary.exponential import log
  from sympy.abc import s, p, a
  from sympy.external import import_module
  from sympy.physics.control.control_plots import pole_zero_numerical_data, pole_zero_plot, step_response_numerical_data, step_response_plot, impulse_response_numerical_data, impulse_response_plot, ramp_response_numerical_data, ramp_response_plot, bode_magnitude_numerical_data, bode_phase_numerical_data, bode_plot
  from sympy.physics.control.lti import TransferFunction, Series, Parallel, TransferFunctionMatrix
  from sympy.testing.pytest import raises, skip
label_desc: Use image node_id 9 for calling a global function with example usage: test_step_response() and returns: unknown