code: def __len__(self):
      return int(np.ceil(len(self.indices) / self.batch_size))
  
file_path: stellargraph/stellargraph/mapper/knowledge_graph.py
imports: import threading
  import numpy
  import pandas
  from tensorflow.keras.utils import Sequence
  from ..globalvar import SOURCE, TARGET, TYPE_ATTR_NAME
  from ..random import random_state, SeededPerBatch
  from .base import Generator
  from ..core.validation import comma_sep, require_integer_in_range
label_desc: Use image node_id 2 for calling the KGTripleSequence obj's underlying member method code with example usage: obj.__len__() and returns: int