text: import torch
  from torch.utils.data import Dataset
  
  from transforms import Wav2Mel
  
  
  class DatasetBase(Dataset):
      def __init__(self, data):
          self.data = data
          self.wav_to_mel = Wav2Mel()
  
      def __len__(self):
          return len(self.data)
  
      def _to_mel(self, wav):
          return self.wav_to_mel(torch.tensor(wav, dtype=torch.float)).squeeze(0)
  
      def __getitem__(self, idx):
          raise NotImplementedError
  