class_docstr: Adds methods related to getting batches from filenames
  
  It includes the logic to transform image files to batches.
code: def sample_weight(self):
      raise NotImplementedError(
          "`sample_weight` property method has not been implemented in {}.".format(
              type(self).__name__
          )
      )
  
imports: import os
  import threading
  import numpy
  from keras_preprocessing import get_keras_submodule
  from .utils import array_to_img, img_to_array, load_img
label_desc: Use image node_id 5 for calling the BatchFromFilesMixin obj's underlying member method code with example usage: obj.sample_weight() without return types