code: def get_proto_variable_inputs(self):
      if self.proto_variable_inputs is None:
          proto_variable_inputs = [
              nn.ProtoVariable(shape) for shape in self.input_shape
          ]
          self.proto_variable_inputs = proto_variable_inputs
          return proto_variable_inputs
      return self.proto_variable_inputs
  
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 3 for calling the ModuleCreator obj's underlying member method code with example usage: obj.get_proto_variable_inputs() and returns: self, proto_variable_inputs