code: def test_unicode_escape(self):
      # test for handling json escaped strings in python 2 Issue #1880
      import json
  
      a = {"a": '{"a": "123"}'}  # an object with many chars to escape
      sa = json.dumps(a)
      G = nx.Graph()
      G.graph["test"] = sa
      fh = io.BytesIO()
      self.writer(G, fh)
      fh.seek(0)
      H = nx.read_graphml(fh)
      assert G.graph["test"] == H.graph["test"]
  
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 20 for calling the TestWriteGraphML obj's underlying member method code with example usage: obj.test_unicode_escape() without return types