code: def test_generator_flow_check_padding():
      generator = PaddedGraphGenerator(graphs=graphs)
  
      seq = generator.flow(graphs=[0, 2], batch_size=2)
      assert isinstance(seq, PaddedGraphSequence)
  
      assert len(seq) == 1
  
      # The largest graph has 6 nodes vs 3 for the smallest one.
      # Check that the data matrices have the correct size 6
      batch = seq[0]
  
      assert batch[0][0].shape == (2, 6, 4)
      assert batch[0][1].shape == (2, 6)
      assert batch[0][2].shape == (2, 6, 6)
  
      for mask in batch[0][1]:
          assert np.sum(mask) == 6 or np.sum(mask) == 3
  
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 11 for calling a global function with example usage: test_generator_flow_check_padding() without return types