text: import scipy
  import spafe
  import pytest
  import numpy as np
  from mock import patch
  from spafe.utils import vis
  from spafe.features.lfcc import lfcc
  from spafe.fbanks import linear_fbanks
  from spafe.utils.exceptions import assert_function_availability
  
  
  @pytest.fixture
  def sig():
      __EXAMPLE_FILE = 'test.wav'
      return scipy.io.wavfile.read(__EXAMPLE_FILE)[1]
  
  
  @pytest.fixture
  def fs():
      __EXAMPLE_FILE = 'test.wav'
      return scipy.io.wavfile.read(__EXAMPLE_FILE)[0]
  
  
  def test_functions_availability():
      # Cheching the availibility of functions in the chosen attribute
      assert_function_availability(hasattr(spafe.utils.vis, 'visualize_fbanks'))
      assert_function_availability(hasattr(spafe.utils.vis,
                                           'visualize_features'))
      assert_function_availability(hasattr(spafe.utils.vis, 'plot'))
      assert_function_availability(hasattr(spafe.utils.vis, 'spectogram'))
  
  
  @patch("matplotlib.pyplot.show")
  def test_visualize_fbanks(mock_show):
      # compute filterbanks
      lin_filbanks = linear_fbanks.linear_filter_banks()
      vis.visualize_fbanks(fbanks=lin_filbanks,
                           ylabel="Amplitude",
                           xlabel="Frequency (Hz)")
  
  
  @patch("matplotlib.pyplot.show")
  def test_visualize_features(sig, fs):
      lfccs = lfcc(sig=sig, fs=fs)
      vis.visualize_features(feats=lfccs,
                             ylabel='LFCC Index',
                             xlabel='Frame Index',
                             cmap='viridis')
  
  
  @patch("matplotlib.pyplot.show")
  def test_plot(mock_show):
      y = np.arange(10)
      vis.plot(y=y, ylabel="y", xlabel="x")
  
  
  @patch("matplotlib.pyplot.show")
  def test_spectogram(sig, fs):
      vis.spectogram(sig, fs)
  