class_docstr: Fits and applies PCA whitening
code: def transform(self, X: Union[np.ndarray, torch.Tensor]):
      return self.apply(X)
  
file_path: vissl/vissl/utils/pca.py
imports: import logging
  from typing import Union
  import numpy
  import torch
  from vissl.utils.io import load_file, save_file
label_desc: Use image node_id 5 for calling the PCA obj's underlying member method code with example usage: obj.transform(X) and returns: self