code: def test_mid(self):
      assert_array_equal(
          waveforms.unit_impulse((3, 3), "mid"),
          [[0, 0, 0], [0, 1, 0], [0, 0, 0]],
      )
      assert_array_equal(
          waveforms.unit_impulse(9, "mid"), [0, 0, 0, 0, 1, 0, 0, 0, 0]
      )
  
imports: from __future__ import division, print_function, absolute_import
  import numpy
  from numpy.testing import assert_almost_equal, assert_equal, assert_, assert_allclose, assert_array_equal
  from pytest import raises
  import scipy.signal.waveforms
label_desc: Use image node_id 3 for calling the TestUnitImpulse obj's underlying member method code with example usage: obj.test_mid() without return types