code: def featureVisualizationDirWrapper(directory):
      if not os.path.isdir(directory):
          raise Exception("Input folder not found!")
      aV.visualizeFeaturesFolder(directory, "pca", "")
  
imports: from __future__ import print_function
  import argparse
  import os
  import numpy
  import glob
  import matplotlib.pyplot
  import ShortTermFeatures
  import MidTermFeatures
  import audioTrainTest
  import audioSegmentation
  import audioVisualization
  import audioBasicIO
  import scipy.io.wavfile
  import matplotlib.patches
label_desc: Use image node_id 6 for calling a global function with example usage: featureVisualizationDirWrapper(directory) without return types