code: def test_generator_flow_no_targets():
      generator = PaddedGraphGenerator(graphs=graphs)
  
      seq = generator.flow(graphs=[0, 1, 2], batch_size=2)
      assert isinstance(seq, PaddedGraphSequence)
  
      assert len(seq) == 2  # two batches
  
      # The first batch should be size 2 and the second batch size 1
      values_0, targets_0 = seq[0]
  
      assert len(values_0) == 3
      assert values_0[0].shape[0] == 2
      assert values_0[1].shape[0] == 2
      assert values_0[2].shape[0] == 2
      assert targets_0 is None
  
      values_1, targets_1 = seq[1]
  
      assert len(values_1) == 3
      assert values_1[0].shape[0] == 1
      assert values_1[1].shape[0] == 1
      assert values_1[2].shape[0] == 1
      assert targets_1 is None
  
imports: from stellargraph.core.graph import *
  from stellargraph.mapper.padded_graph_generator import PaddedGraphGenerator, PaddedGraphSequence
  import numpy
  import pytest
  from ..test_utils.graphs import example_graph_random, example_graph, example_hin_1
label_desc: Use image node_id 10 for calling a global function with example usage: test_generator_flow_no_targets() without return types