code: def test_dstep_2(self, xp, scp):
      # Check that the other two inputs (tf, zpk) will work as well
      tfin = ([1.0], [1.0, 1.0], 0.5)
      tout, yout = scp.signal.dstep(tfin, n=3)
      return tout, *yout
  
imports: from math import sqrt, pi
  from pytest import raises
  import cupy
  from cupy import testing
  import cupyx.scipy.signal
label_desc: Use image node_id 9 for calling the TestDLTI obj's underlying member method code with example usage: obj.test_dstep_2(xp, scp) and returns: tout,  unknown