code: def test_meanpool_agg_constructor():
      agg = MeanPoolingAggregator(2, bias=False)
      assert agg.output_dim == 2
      assert agg.hidden_dim == 2
      assert not agg.has_bias
      assert agg.act.__name__ == "relu"
      assert agg.hidden_act.__name__ == "relu"
  
      # Check config
      config = agg.get_config()
      assert config["output_dim"] == 2
      assert config["bias"] is False
      assert config["act"] == "relu"
  
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 11 for calling a global function with example usage: test_meanpool_agg_constructor() without return types