code: def two_node_graph():
      graph = nx.Graph()
      graph.add_nodes_from([1, 2])
      graph.add_edges_from([(1, 2)])
      return graph
  
imports: import itertools
  import pytest
  import networkx
label_desc: Use image node_id 6 for calling a global function with example usage: two_node_graph() and returns: graph