code: def test_dtype(self):
      imp = waveforms.unit_impulse(7)
      assert_(np.issubdtype(imp.dtype, np.floating))
  
      imp = waveforms.unit_impulse(5, 3, dtype=int)
      assert_(np.issubdtype(imp.dtype, np.integer))
  
      imp = waveforms.unit_impulse((5, 2), (3, 1), dtype=complex)
      assert_(np.issubdtype(imp.dtype, np.complexfloating))
  
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 4 for calling the TestUnitImpulse obj's underlying member method code with example usage: obj.test_dtype() without return types