code: def test_mixed_type_attributes(self):
      G = nx.MultiGraph()
      G.add_node("n0", special=False)
      G.add_node("n1", special=0)
      G.add_edge("n0", "n1", special=False)
      G.add_edge("n0", "n1", special=0)
      fh = io.BytesIO()
      self.writer(G, fh)
      fh.seek(0)
      H = nx.read_graphml(fh)
      assert not H.nodes["n0"]["special"]
      assert H.nodes["n1"]["special"] == 0
      assert not H.edges["n0", "n1", 0]["special"]
      assert H.edges["n0", "n1", 1]["special"] == 0
  
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 10 for calling the TestWriteGraphML obj's underlying member method code with example usage: obj.test_mixed_type_attributes() without return types