docstr: Verify that no peak is found in
  data that's just noise.
docstr_tok: ["Verify","that","no","peak","is","found","in","data","that","'s","just","noise","."]
code: def test_find_peaks_nopeak(self):
      """
      Verify that no peak is found in
      data that's just noise.
      """
      noise_amp = 1.0
      num_points = 100
      np.random.seed(181819141)
      test_data = (np.random.rand(num_points) - 0.5) * (2 * noise_amp)
      widths = np.arange(10, 50)
      found_locs = find_peaks_cwt(
          test_data, widths, min_snr=5, noise_perc=30
      )
      np.testing.assert_equal(len(found_locs), 0)
  
imports: from __future__ import division, print_function, absolute_import
  import copy
  import numpy
  from numpy.testing import assert_, assert_equal, assert_allclose, assert_array_equal
  import pytest
  from pytest import raises, warns
  from scipy._lib.six import xrange
  from scipy.signal._peak_finding import argrelmax, argrelmin, peak_prominences, peak_widths, _unpack_condition_args, find_peaks, find_peaks_cwt, _identify_ridge_lines
  from scipy.signal._peak_finding_utils import _local_maxima_1d, PeakPropertyWarning
label_desc: Use image node_id 3 for calling the TestFindPeaksCwt obj's underlying member method code with example usage: obj.test_find_peaks_nopeak() without return types