code: def test_kernel_and_bias_defaults():
      graph, _ = create_graph_features()
      generator = FullBatchNodeGenerator(
          graph, sparse=False, method="none"
      )
      gcn = GCN([2, 2], generator)
  
      for layer in gcn._layers:
          if isinstance(layer, GraphConvolution):
              assert isinstance(
                  layer.kernel_initializer,
                  tf.initializers.GlorotUniform,
              )
              assert isinstance(
                  layer.bias_initializer, tf.initializers.Zeros
              )
              assert layer.kernel_regularizer is None
              assert layer.bias_regularizer is None
              assert layer.kernel_constraint is None
              assert layer.bias_constraint is None
  
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 12 for calling a global function with example usage: test_kernel_and_bias_defaults() without return types