code: def test_generator_flow_invalid_batch_size():
      with pytest.raises(
          ValueError,
          match="expected batch_size.*strictly positive integer, found -1",
      ):
          PaddedGraphGenerator(graphs=graphs).flow(
              graphs=[0], batch_size=-1
          )
  
      with pytest.raises(
          TypeError,
          match="expected batch_size.*integer type, found float",
      ):
          PaddedGraphGenerator(graphs=graphs).flow(
              graphs=[0], batch_size=2.0
          )
  
      with pytest.raises(
          ValueError,
          match="expected batch_size.*strictly positive integer, found 0",
      ):
          PaddedGraphGenerator(graphs=graphs).flow(
              graphs=[0], batch_size=0
          )
  
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 7 for calling a global function with example usage: test_generator_flow_invalid_batch_size() without return types