code: def test_sliding_sequence_no_targets(variates):
      g = _graph(_SHAPES[variates])
      single, several = _feat_getters(g)
      everything = slice(None)
  
      # extreme case: window_size = 1
      gen1 = SlidingFeaturesNodeGenerator(
          g, window_size=1, batch_size=3
      )
      seq = gen1.flow(everything)
      _check_sequence(
          seq,
          [
              ([several(0, 1), several(1, 2), several(2, 3)], None),
              ([several(3, 4)], None),
          ],
      )
  
      gen2 = SlidingFeaturesNodeGenerator(
          g, window_size=2, batch_size=2
      )
      seq = gen2.flow(everything)
      _check_sequence(
          seq,
          [
              ([several(0, 2), several(1, 3)], None),
              ([several(2, 4)], None),
          ],
      )
  
file_path: stellargraph/tests/mapper/test_sliding.py
imports: import numpy
  import pytest
  from stellargraph import StellarGraph
  from stellargraph.mapper import SlidingFeaturesNodeGenerator, SlidingFeaturesNodeSequence
  from ..test_utils.graphs import example_graph, example_hin_1
label_desc: Use image node_id 7 for calling a global function with example usage: test_sliding_sequence_no_targets(variates) without return types