class_docstr: WaveRNN Dataset searchs for all the wav files under root path
  and converts them to acoustic features on the fly.
code: def __getitem__(self, index):
      item = self.load_item(index)
      return item
  
file_path: TTS/TTS/vocoder/datasets/wavernn_dataset.py
imports: import torch
  import numpy
  from torch.utils.data import Dataset
label_desc: Use image node_id 3 for calling the WaveRNNDataset obj's underlying member method code with example usage: obj.__getitem__(index) and returns: item