code: def test_closure(self):
      ind1 = Independencies(("A", ["B", "C"], "D"))
      self.assertEqual(
          ind1.closure(),
          Independencies(
              ("A", ["B", "C"], "D"),
              ("A", "B", ["C", "D"]),
              ("A", "C", ["B", "D"]),
              ("A", "B", "D"),
              ("A", "C", "D"),
          ),
      )
      ind2 = Independencies(("W", ["X", "Y", "Z"]))
      self.assertEqual(
          ind2.closure(),
          Independencies(
              ("W", "Y"),
              ("W", "Y", "X"),
              ("W", "Y", "Z"),
              ("W", "Y", ["X", "Z"]),
              ("W", ["Y", "X"]),
              ("W", "X", ["Y", "Z"]),
              ("W", ["X", "Z"], "Y"),
              ("W", "X"),
              ("W", ["X", "Z"]),
              ("W", ["Y", "Z"], "X"),
              ("W", ["Y", "X", "Z"]),
              ("W", "X", "Z"),
              ("W", ["Y", "Z"]),
              ("W", "Z", "X"),
              ("W", "Z"),
              ("W", ["Y", "X"], "Z"),
              ("W", "X", "Y"),
              ("W", "Z", ["Y", "X"]),
              ("W", "Z", "Y"),
          ),
      )
      ind3 = Independencies(
          ("c", "a", ["b", "e", "d"]),
          (["e", "c"], "b", ["a", "d"]),
          (["b", "d"], "e", "a"),
          ("e", ["b", "d"], "c"),
          ("e", ["b", "c"], "d"),
          (["e", "c"], "a", "b"),
      )
      self.assertEqual(len(ind3.closure().get_assertions()), 78)
  
imports: import unittest
  from pgmpy.independencies import Independencies, IndependenceAssertion
label_desc: Use image node_id 6 for calling the TestIndependencies obj's underlying member method code with example usage: obj.test_closure() without return types