code: def test_plotly_relayout_nested_array(self):
      # Initialize images
      self.figure.layout.updatemenus = [
          {},
          go.layout.Updatemenu(
              buttons=[
                  {},
                  {},
                  go.layout.updatemenu.Button(method="relayout"),
              ]
          ),
          {},
      ]
  
      self.figure._send_relayout_msg.assert_called_once_with(
          {
              "updatemenus": [
                  {},
                  {"buttons": [{}, {}, {"method": "relayout"}]},
                  {},
              ]
          }
      )
  
      # Reset mock and perform property assignment
      self.figure._send_relayout_msg = MagicMock()
  
      self.figure.plotly_relayout(
          {"updatemenus[1].buttons.0.method": "restyle"}
      )
      self.figure._send_relayout_msg.assert_called_once_with(
          {"updatemenus[1].buttons.0.method": "restyle"}
      )
  
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 10 for calling the TestRelayoutMessage obj's underlying member method code with example usage: obj.test_plotly_relayout_nested_array() without return types