code: def dump_network_topology(network):
      class Verifier:
          def __call__(self, pf):
              inputs = ",".join(pf.inputs)
              outputs = ",".join(pf.outputs)
              print(
                  "{}:{}, i:{}, o:{}".format(
                      pf.type, pf.name, inputs, outputs
                  )
              )
  
      network.execute_on_proto(Verifier())
  
imports: import os
  import io
  import pytest
  import numpy
  import nnabla
  import nnabla.functions
  from nnabla.testing import assert_allclose
  from contextlib import contextmanager
  from shutil import rmtree
  import tempfile
  import numpy
  import warnings
  from legacy_expander import NnpExpander
  from nnabla.utils import nnabla_pb2
  from legacy_load import _create_variable
  import google.protobuf.text_format
  from nnabla.utils.image_utils import imsave
  from nnabla.utils.get_file_handle import get_file_handle_save
  from nnabla.utils.nnp_format import nnp_version
label_desc: Use image node_id 15 for calling a global function with example usage: dump_network_topology(network) without return types