code: def test_cascade(self):
      for J in xrange(1, 7):
          for i in xrange(1, 5):
              lpcoef = wavelets.daub(i)
              k = len(lpcoef)
              x, phi, psi = wavelets.cascade(lpcoef, J)
              assert_(len(x) == len(phi) == len(psi))
              assert_equal(len(x), (k - 1) * 2**J)
  
file_path: catboost/contrib/python/scipy/py2/scipy/signal/tests/test_wavelets.py
imports: from __future__ import division, print_function, absolute_import
  import numpy
  from numpy.testing import assert_equal, assert_array_equal, assert_array_almost_equal, assert_array_less, assert_
  from scipy._lib.six import xrange
  from scipy.signal import wavelets
label_desc: Use image node_id 3 for calling the TestWavelets obj's underlying member method code with example usage: obj.test_cascade() without return types