code: def test_custom_layout_default_height(self):
      layout = FigureLayout(width="712px", border="1px solid blue")
      fig = figure(layout=layout)
      assert fig.layout.height == "420px"
  
imports: import unittest
  import traitlets
  from ..figure import figure, Figure, FigureLayout
  from ..maps import Map
  from ..toolbar import Toolbar
  from ..errors_box import ErrorsBox
label_desc: Use image node_id 8 for calling the TestFigureFactory obj's underlying member method code with example usage: obj.test_custom_layout_default_height() without return types