docstr: Test if wlen actually shrinks the evaluation range correctly.
docstr_tok: ["Test","if","wlen","actually","shrinks","the","evaluation","range","correctly","."]
code: def test_wlen(self, wlen, xp, scp):
      """
      Test if wlen actually shrinks the evaluation range correctly.
      """
      x = xp.asarray([0, 1, 2, 3.0, 1, 0, -1])
      peak = xp.asarray([3])
      return scp.signal.peak_prominences(x, peak, wlen)
  
imports: import pytest
  import cupy
  from cupy.cuda import driver
  from cupy.cuda import runtime
  from cupy import testing
  import cupyx.scipy.signal
  import numpy
label_desc: Use image node_id 5 for calling the TestPeakProminences obj's underlying member method code with example usage: obj.test_wlen(wlen, xp, scp) and returns: scp