code: def test_init(self):
      self.assertion1 = IndependenceAssertion("U", "V", "Z")
      self.assertSetEqual(self.assertion1.event1, {"U"})
      self.assertSetEqual(self.assertion1.event2, {"V"})
      self.assertSetEqual(self.assertion1.event3, {"Z"})
      self.assertion1 = IndependenceAssertion(
          ["U", "V"], ["Y", "Z"], ["A", "B"]
      )
      self.assertSetEqual(self.assertion1.event1, {"U", "V"})
      self.assertSetEqual(self.assertion1.event2, {"Y", "Z"})
      self.assertSetEqual(self.assertion1.event3, {"A", "B"})
  
imports: import unittest
  from pgmpy.independencies import Independencies, IndependenceAssertion
label_desc: Use image node_id 4 for calling the TestIndependenceAssertion obj's underlying member method code with example usage: obj.test_init() without return types