code: def test_node_default_attribute_graphml(self):
      G = self.node_attribute_default_graph
      H = nx.read_graphml(self.node_attribute_default_fh)
      assert G.graph["node_default"] == H.graph["node_default"]
  
imports: import io
  import pytest
  import networkx
  from networkx.readwrite.graphml import GraphMLWriter
  from networkx.utils import edges_equal, nodes_equal
label_desc: Use image node_id 7 for calling the TestReadGraphML obj's underlying member method code with example usage: obj.test_node_default_attribute_graphml() without return types