docstr: Check that hann_window matches scipy.signal.hann behavior.
docstr_tok: ["Check","that","hann_window","matches","scipy.signal.hann","behavior","."]
code: def test_hann_window(self, window_length, periodic, tf_dtype_tol):
      """Check that hann_window matches scipy.signal.hann behavior."""
      # The Hann window is a raised cosine window with parameters alpha=0.5 and
      # beta=0.5.
      # https://en.wikipedia.org/wiki/Window_function#Hann_window
      self._compare_window_fns(
          functools.partial(_scipy_raised_cosine, a=0.5, b=0.5),
          window_ops.hann_window,
          window_length,
          periodic,
          tf_dtype_tol,
      )
  
imports: import functools
  import itertools
  from absl.testing import parameterized
  import numpy
  from tensorflow.python.eager import context
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor_spec
  from tensorflow.python.framework import test_util
  from tensorflow.python.kernel_tests.signal import test_util
  from tensorflow.python.ops.signal import window_ops
  from tensorflow.python.platform import test
label_desc: Use image node_id 4 for calling the WindowOpsTest obj's underlying member method code with example usage: obj.test_hann_window(window_length, periodic, tf_dtype_tol) without return types