code: def test_graphsage_save_load(tmpdir):
      gs = GraphSAGE(
          layer_sizes=[4, 4],
          n_samples=[2, 2],
          input_dim=2,
          multiplicity=1,
      )
      test_utils.model_save_load(tmpdir, gs)
  
imports: from tensorflow import keras
  from tensorflow.keras import initializers, regularizers
  import tensorflow
  import numpy
  import pytest
  from stellargraph.mapper import GraphSAGENodeGenerator
  from stellargraph.layer.graphsage import GraphSAGE, MeanAggregator, MaxPoolingAggregator, MeanPoolingAggregator, AttentionalAggregator
  from ..test_utils.graphs import example_graph
  from ..None import test_utils
label_desc: Use image node_id 30 for calling a global function with example usage: test_graphsage_save_load(tmpdir) without return types