code: def sl_shc():
      graph = nx.Graph()
      graph.add_nodes_from([1, 2, 3, 4, 5, 6])
      graph.add_edges_from(
          [
              (1, 2),
              (1, 3),
              (2, 3),
              (1, 4),
              (2, 5),
              (3, 6),
              (4, 5),
              (4, 6),
              (5, 6),
          ]
      )
      return graph
  
imports: import itertools
  import pytest
  import networkx
label_desc: Use image node_id 14 for calling a global function with example usage: sl_shc() and returns: graph