code: def test_get_states(self):
      self.assertDictEqual(
          self.writer.get_states(),
          {
              "asia": ["yes", "no"],
              "bronc": ["yes", "no"],
              "dysp": ["yes", "no"],
              "either": ["yes", "no"],
              "lung": ["yes", "no"],
              "smoke": ["yes", "no"],
              "tub": ["yes", "no"],
              "xray": ["yes", "no"],
          },
      )
  
imports: import unittest
  import numpy
  from pgmpy import config
  from pgmpy.readwrite import NETReader, NETWriter
  from pgmpy.utils import compat_fns, get_example_model
label_desc: Use image node_id 3 for calling the TestNETWriter obj's underlying member method code with example usage: obj.test_get_states() without return types