code: def test_demo_param_init(self):
      self.assertDictEqual(
          self.demo_params.graph.edges[("xi1", "x1")], {"weight": 0.4}
      )
      self.assertDictEqual(
          self.demo_params.graph.edges[("xi1", "x2")], {"weight": 0.5}
      )
      self.assertDictEqual(
          self.demo_params.graph.edges[("xi1", "x3")], {"weight": 0.6}
      )
      self.assertDictEqual(
          self.demo_params.graph.edges[("xi1", "eta1")], {"weight": 0.3}
      )
      self.assertDictEqual(
          self.demo_params.graph.edges[("eta1", "y1")], {"weight": 1.1}
      )
      self.assertDictEqual(
          self.demo_params.graph.edges[("eta1", "y2")], {"weight": 1.2}
      )
      self.assertDictEqual(
          self.demo_params.graph.edges[("eta1", "y3")], {"weight": 1.3}
      )
      self.assertDictEqual(
          self.demo_params.graph.edges[("eta1", "y4")], {"weight": 1.4}
      )
      self.assertDictEqual(
          self.demo_params.graph.edges[("eta1", "eta2")],
          {"weight": 0.1},
      )
      self.assertDictEqual(
          self.demo_params.graph.edges[("xi1", "eta2")], {"weight": 0.2}
      )
      self.assertDictEqual(
          self.demo_params.graph.edges[("eta2", "y5")], {"weight": 0.7}
      )
      self.assertDictEqual(
          self.demo_params.graph.edges[("eta2", "y6")], {"weight": 0.8}
      )
      self.assertDictEqual(
          self.demo_params.graph.edges[("eta2", "y7")], {"weight": 0.9}
      )
      self.assertDictEqual(
          self.demo_params.graph.edges[("eta2", "y8")], {"weight": 1.0}
      )
  
      self.assertDictEqual(
          self.demo_params.err_graph.edges[("y1", "y5")],
          {"weight": 1.5},
      )
      self.assertDictEqual(
          self.demo_params.err_graph.edges[("y2", "y6")],
          {"weight": 1.6},
      )
      self.assertDictEqual(
          self.demo_params.err_graph.edges[("y2", "y4")],
          {"weight": 1.9},
      )
      self.assertDictEqual(
          self.demo_params.err_graph.edges[("y3", "y7")],
          {"weight": 1.7},
      )
      self.assertDictEqual(
          self.demo_params.err_graph.edges[("y4", "y8")],
          {"weight": 1.8},
      )
      self.assertDictEqual(
          self.demo_params.err_graph.edges[("y6", "y8")],
          {"weight": 2.0},
      )
  
      self.assertDictEqual(
          self.demo_params.err_graph.nodes["y1"], {"weight": 2.1}
      )
      self.assertDictEqual(
          self.demo_params.err_graph.nodes["y2"], {"weight": 2.2}
      )
      self.assertDictEqual(
          self.demo_params.err_graph.nodes["y3"], {"weight": 2.3}
      )
      self.assertDictEqual(
          self.demo_params.err_graph.nodes["y4"], {"weight": 2.4}
      )
      self.assertDictEqual(
          self.demo_params.err_graph.nodes["y5"], {"weight": 2.5}
      )
      self.assertDictEqual(
          self.demo_params.err_graph.nodes["y6"], {"weight": 2.6}
      )
      self.assertDictEqual(
          self.demo_params.err_graph.nodes["y7"], {"weight": 2.7}
      )
      self.assertDictEqual(
          self.demo_params.err_graph.nodes["y8"], {"weight": 2.8}
      )
      self.assertDictEqual(
          self.demo_params.err_graph.nodes["x1"], {"weight": 3.1}
      )
      self.assertDictEqual(
          self.demo_params.err_graph.nodes["x2"], {"weight": 3.2}
      )
      self.assertDictEqual(
          self.demo_params.err_graph.nodes["x3"], {"weight": 3.3}
      )
      self.assertDictEqual(
          self.demo_params.err_graph.nodes["eta1"], {"weight": 2.9}
      )
      self.assertDictEqual(
          self.demo_params.err_graph.nodes["eta2"], {"weight": 3.0}
      )
  
imports: import os
  import unittest
  import networkx
  import numpy
  import numpy.testing
  from pgmpy.models import SEM, SEMAlg, SEMGraph
label_desc: Use image node_id 4 for calling the TestSEMGraph obj's underlying member method code with example usage: obj.test_demo_param_init() without return types