code: def __len__(self):
      return int(math.ceil(self.X.shape[0] / float(self.batch_size)))
  
imports: from abc import ABC, abstractmethod
  from functools import partial
  import itertools
  import random
  import math
  import numpy
  from tensorflow.keras.utils import Sequence
  from scipy.sparse import issparse
  from ..data import get_uint_ctype
label_desc: Use image node_id 2 for calling the TripletGenerator obj's underlying member method code with example usage: obj.__len__() and returns: int