code: def test_electrocardiogram():
      # Test shape, dtype and stats of signal
      ecg = electrocardiogram()
      assert ecg.dtype == float
      assert_equal(ecg.shape, (108000,))
      assert_almost_equal(ecg.mean(), -0.16510875)
      assert_almost_equal(ecg.std(), 0.5992473991177294)
  
imports: from numpy.testing import assert_equal, assert_almost_equal
  from scipy.misc import face, ascent, electrocardiogram
label_desc: Use image node_id 3 for calling a global function with example usage: test_electrocardiogram() without return types