class_docstr: Lighting noise(AlexNet - style PCA - based noise)
code: def __call__(self, img):
      if self.alphastd == 0:
          return img
  
      alpha = img.new().resize_(3).normal_(0, self.alphastd)
      rgb = (
          self.eigvec.type_as(img)
          .clone()
          .mul(alpha.view(1, 3).expand(3, 3))
          .mul(self.eigval.view(1, 3).expand(3, 3))
          .sum(1)
          .squeeze()
      )
  
      return img.add(rgb.view(3, 1, 1).expand_as(img))
  
imports: import random
  import numpy
  import PIL
  import PIL.ImageDraw
  import PIL.ImageEnhance
  import PIL.ImageOps
  import torch
  from PIL import Image
label_desc: Use image node_id 2 for calling the Lighting obj's underlying member method code with example usage: obj.__call__(img) and returns: img, img