code: def example_graph():
      G = nx.Graph()
      G.add_weighted_edges_from(
          [(1, 2, 3.0), (2, 3, 27.0), (3, 4, 3.0)]
      )
      return G
  
imports: import io
  import textwrap
  import pytest
  import networkx
  from networkx.utils import edges_equal, graphs_equal, nodes_equal
label_desc: Use image node_id 4 for calling a global function with example usage: example_graph() and returns: G