code: def test_GraphConvolution_init():
      gcn_layer = GraphConvolution(units=16, activation="relu")
  
      assert gcn_layer.units == 16
      assert gcn_layer.use_bias == True
      assert gcn_layer.get_config()["activation"] == "relu"
  
imports: import stellargraph
  from stellargraph.layer.gcn import *
  from stellargraph.mapper import FullBatchNodeGenerator, FullBatchLinkGenerator
  from stellargraph.core.graph import StellarGraph
  from stellargraph.core.utils import GCN_Aadj_feats_op
  import networkx
  import pandas
  import numpy
  from tensorflow import keras
  import tensorflow
  import pytest
  from ..test_utils.graphs import create_graph_features
  from ..None import test_utils
label_desc: Use image node_id 2 for calling a global function with example usage: test_GraphConvolution_init() without return types