code: def test_multiline(self):
      # example from issue #6836
      multiline_example = """
  graph
  [
      node
      [
  	    id 0
  	    label "multiline node"
  	    label2 "multiline1
      multiline2
      multiline3"
  	    alt_name "id 0"
      ]
  ]
  """
      G = nx.parse_gml(multiline_example)
      assert G.nodes["multiline node"] == {
          "label2": "multiline1 multiline2 multiline3",
          "alt_name": "id 0",
      }
  
imports: import codecs
  import io
  import math
  from ast import literal_eval
  from contextlib import contextmanager
  from textwrap import dedent
  import pytest
  import networkx
  from networkx.readwrite.gml import literal_destringizer, literal_stringizer
label_desc: Use image node_id 19 for calling the TestGraph obj's underlying member method code with example usage: obj.test_multiline() without return types