code: def test_dlsim_7(self):
      # Raise an error for continuous-time systems
      system = signal.lti([1], [1, 1])
      u = cupy.hstack(
          (
              cupy.linspace(0, 4.0, num=5)[:, None],
              cupy.full((5, 1), 0.01),
              cupy.full((5, 1), -0.002),
          )
      )
      with assert_raises(AttributeError):
          signal.dlsim(system, u)
  
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 7 for calling the TestDLTI obj's underlying member method code with example usage: obj.test_dlsim_7() without return types