docstr: Test with simple signal.
docstr_tok: ["Test","with","simple","signal","."]
code: def test_simple(self):
      """Test with simple signal."""
      x = np.linspace(-10, 10, 50)
      x[2::3] += 1
      expected = np.arange(2, 50, 3)
      for array in _local_maxima_1d(x):
          # For plateaus of size 1, the edges are identical with the
          # midpoints
          assert_equal(array, expected)
          assert_(array.base is None)
  
imports: 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.signal._peak_finding import argrelmax, argrelmin, peak_prominences, peak_widths, _unpack_condition_args, find_peaks, find_peaks_cwt, _identify_ridge_lines
  from scipy.signal.windows import gaussian
  from scipy.signal._peak_finding_utils import _local_maxima_1d, PeakPropertyWarning
label_desc: Use image node_id 3 for calling the TestLocalMaxima1d obj's underlying member method code with example usage: obj.test_simple() without return types