code: def test_states(self):
      self.assertDictEqual(
          self.graph4.states,
          {
              "a": [0, 1],
              "b": [0, 1],
              "e": [0, 1],
              "c": [0, 1],
              "d": [0, 1],
              "f": [0, 1],
          },
      )
  
imports: import unittest
  import numpy
  from pgmpy.factors.discrete import DiscreteFactor
  from pgmpy.models import JunctionTree
  from pgmpy.tests import help_functions
label_desc: Use image node_id 3 for calling the TestJunctionTreeMethods obj's underlying member method code with example usage: obj.test_states() without return types