code: def __getitem__(self, batch_num):
      first_start = batch_num * self._batch_size
      last_start = min(
          (batch_num + 1) * self._batch_size, self._num_windows
      )
  
      has_targets = self._target_distance is not None
  
      arrays = []
      targets = [] if has_targets else None
      for start in range(first_start, last_start):
          end = start + self._window_size
          arrays.append(self._features[:, start:end, ...])
          if has_targets:
              target_idx = end + self._target_distance - 1
              targets.append(self._features[:, target_idx, ...])
  
      this_batch_size = last_start - first_start
  
      batch_feats = np.stack(arrays)
      assert (
          batch_feats.shape
          == (this_batch_size, self._num_nodes, self._window_size)
          + self._num_sequence_variates
      )
  
      if has_targets:
          batch_targets = np.stack(targets)
          assert (
              batch_targets.shape
              == (this_batch_size, self._num_nodes)
              + self._num_sequence_variates
          )
      else:
          batch_targets = None
  
      return [batch_feats], batch_targets
  
file_path: stellargraph/stellargraph/mapper/sliding.py
imports: import numpy
  from .None import Generator
  from tensorflow.keras.utils import Sequence
  from ..core.validation import require_integer_in_range
label_desc: Use image node_id 3 for calling the SlidingFeaturesNodeSequence obj's underlying member method code with example usage: obj.__getitem__(batch_num) and returns: list,  batch_targets