class_docstr: time mask
docstr: Args:
      img (numpy.ndarray): Images to be masked.
  Returns:
      numpy.ndarray: Masked image.
docstr_tok: ["Args",":","img","(","numpy.ndarray",")",":","Images","to","be","masked",".","Returns",":","numpy.ndarray",":","Masked","image","."]
code: def __call__(self, img):
      """
      Args:
          img (numpy.ndarray): Images to be masked.
      Returns:
          numpy.ndarray: Masked image.
      """
      frames, h, w = img.shape
      max_mask_length = min(frames, self.max_mask_length)
  
      mask_length = random.randint(0, max_mask_length)
      start = random.randint(0, frames - mask_length)
  
      img[start : start + mask_length] = 0.0
      return img
  
imports: import random
  import cv2
  import numpy
  import torch
  from scipy import signal
label_desc: Use image node_id 2 for calling the TimeMask obj's underlying member method code with example usage: obj.__call__(img) and returns: img