code: def sprinkler_graph():
      """The Sprinkler Example as a BBN
      to be used in tests.
      """
      cloudy = Node("Cloudy")
      sprinkler = Node("Sprinkler")
      rain = Node("Rain")
      wet_grass = Node("WetGrass")
      cloudy.children = [sprinkler, rain]
      sprinkler.parents = [cloudy]
      sprinkler.children = [wet_grass]
      rain.parents = [cloudy]
      rain.children = [wet_grass]
      wet_grass.parents = [sprinkler, rain]
      bbn = BBN(
          {
              "cloudy": cloudy,
              "sprinkler": sprinkler,
              "rain": rain,
              "wet_grass": wet_grass,
          }
      )
      return bbn
  
file_path: causalnex/tests/ebaybbn/conftest.py
imports: import pytest
  from causalnex.ebaybbn import BBN, Node, build_bbn, build_join_tree, combinations, make_moralized_copy, make_undirected_copy
  from causalnex.ebaybbn.utils import make_key
label_desc: Use image node_id 1 for calling a global function with example usage: sprinkler_graph() and returns: bbn