code: def test_sines_plus(self, xp, scp, func):
      x = xp.zeros(100, dtype=complex)
      x[[1, 5, 21]] = 1
      x += 1j * xp.linspace(0, 0.5, x.shape[0])
      return func(x, xp, scp)
  
imports: from math import pi
  import pytest
  import cupy
  import numpy
  from cupy import testing
  from cupy.testing import assert_allclose
  import cupyx.scipy.fft
  import cupyx.scipy.signal
label_desc: Use image node_id 6 for calling the Test1D obj's underlying member method code with example usage: obj.test_sines_plus(xp, scp, func) and returns: func