code: def test_invalid_args(self):
      # `freq` and `gain` have different lengths.
      with assert_raises(ValueError, match="must be of same length"):
          firwin2(50, [0, 0.5, 1], [0.0, 1.0])
      # `nfreqs` is less than `ntaps`.
      with assert_raises(
          ValueError, match="ntaps must be less than nfreqs"
      ):
          firwin2(50, [0, 0.5, 1], [0.0, 1.0, 1.0], nfreqs=33)
      # Decreasing value in `freq`
      with assert_raises(ValueError, match="must be nondecreasing"):
          firwin2(50, [0, 0.5, 0.4, 1.0], [0, 0.25, 0.5, 1.0])
      # Value in `freq` repeated more than once.
      with assert_raises(
          ValueError, match="must not occur more than twice"
      ):
          firwin2(
              50, [0, 0.1, 0.1, 0.1, 1.0], [0.0, 0.5, 0.75, 1.0, 1.0]
          )
      # `freq` does not start at 0.0.
      with assert_raises(ValueError, match="start with 0"):
          firwin2(50, [0.5, 1.0], [0.0, 1.0])
      # `freq` does not end at fs/2.
      with assert_raises(ValueError, match="end with fs/2"):
          firwin2(50, [0.0, 0.5], [0.0, 1.0])
      # Value 0 is repeated in `freq`
      with assert_raises(ValueError, match="0 must not be repeated"):
          firwin2(50, [0.0, 0.0, 0.5, 1.0], [1.0, 1.0, 0.0, 0.0])
      # Value fs/2 is repeated in `freq`
      with assert_raises(ValueError, match="fs/2 must not be repeated"):
          firwin2(50, [0.0, 0.5, 1.0, 1.0], [1.0, 1.0, 0.0, 0.0])
      # Value in `freq` that is too close to a repeated number
      with assert_raises(
          ValueError,
          match="cannot contain numbers " "that are too close",
      ):
          firwin2(
              50,
              [0.0, 0.5 - np.finfo(float).eps * 0.5, 0.5, 0.5, 1.0],
              [1.0, 1.0, 1.0, 0.0, 0.0],
          )
  
      # Type II filter, but the gain at nyquist frequency is not zero.
      with assert_raises(ValueError, match="Type II filter"):
          firwin2(16, [0.0, 0.5, 1.0], [0.0, 1.0, 1.0])
  
      # Type III filter, but the gains at nyquist and zero rate are not zero.
      with assert_raises(ValueError, match="Type III filter"):
          firwin2(
              17, [0.0, 0.5, 1.0], [0.0, 1.0, 1.0], antisymmetric=True
          )
      with assert_raises(ValueError, match="Type III filter"):
          firwin2(
              17, [0.0, 0.5, 1.0], [1.0, 1.0, 0.0], antisymmetric=True
          )
      with assert_raises(ValueError, match="Type III filter"):
          firwin2(
              17, [0.0, 0.5, 1.0], [1.0, 1.0, 1.0], antisymmetric=True
          )
  
      # Type IV filter, but the gain at zero rate is not zero.
      with assert_raises(ValueError, match="Type IV filter"):
          firwin2(
              16, [0.0, 0.5, 1.0], [1.0, 1.0, 0.0], antisymmetric=True
          )
  
imports: import numpy
  from numpy.testing import assert_almost_equal, assert_array_almost_equal, assert_equal, assert_, assert_allclose, assert_warns
  from pytest import raises
  import pytest
  from scipy.fft import fft
  from scipy.special import sinc
  from scipy.signal import kaiser_beta, kaiser_atten, kaiserord, firwin, firwin2, freqz, remez, firls, minimum_phase
label_desc: Use image node_id 1 for calling the TestFirwin2 obj's underlying member method code with example usage: obj.test_invalid_args() without return types