code: def test_property_assignment_nested_subplot2(self):
      # Initialize xaxis2
      self.figure.layout.xaxis2 = {"range": [0, 1]}
      self.figure._send_relayout_msg.assert_called_once_with(
          {"xaxis2": {"range": [0, 1]}}
      )
  
      # Reset mock and perform property assignment
      self.figure._send_relayout_msg = MagicMock()
      self.figure.layout.xaxis2.title.font.family = "courier"
      self.figure._send_relayout_msg.assert_called_once_with(
          {"xaxis2.title.font.family": "courier"}
      )
  
file_path: plotly.py/packages/python/plotly/plotly/tests/test_core/test_figure_messages/test_plotly_relayout.py
imports: import sys
  from unittest import TestCase
  import plotly.graph_objs
label_desc: Use image node_id 4 for calling the TestRelayoutMessage obj's underlying member method code with example usage: obj.test_property_assignment_nested_subplot2() without return types