code: def test_definition(self):
      for n in [18, 17, 64, 127, 32, 2048, 256]:
          x = arange(n) * 2 * pi / n
          for a in [0.1, 3]:
              assert_array_almost_equal(
                  shift(sin(x), a), direct_shift(sin(x), a)
              )
              assert_array_almost_equal(shift(sin(x), a), sin(x + a))
              assert_array_almost_equal(shift(cos(x), a), cos(x + a))
              assert_array_almost_equal(
                  shift(cos(2 * x) + sin(x), a),
                  cos(2 * (x + a)) + sin(x + a),
              )
              assert_array_almost_equal(
                  shift(exp(sin(x)), a), exp(sin(x + a))
              )
          assert_array_almost_equal(shift(sin(x), 2 * pi), sin(x))
          assert_array_almost_equal(shift(sin(x), pi), -sin(x))
          assert_array_almost_equal(shift(sin(x), pi / 2), cos(x))
  
imports: from numpy.testing import assert_equal, assert_almost_equal, assert_array_almost_equal
  from scipy.fftpack import diff, fft, ifft, tilbert, itilbert, hilbert, ihilbert, shift, fftfreq, cs_diff, sc_diff, ss_diff, cc_diff
  import numpy
  from numpy import arange, sin, cos, pi, exp, tanh, sum, sign
  from numpy.random import random
label_desc: Use image node_id 1 for calling the TestShift obj's underlying member method code with example usage: obj.test_definition() without return types