code: def test_template_default_override(self):
      pio.templates.default = "test_template"
      template = go.layout.Template(layout={"font": {"size": 30}})
      fig = go.Figure(layout={"template": template})
      self.assertEqual(fig.layout.template, template)
  
imports: import copy
  from unittest import TestCase
  import pytest
  import plotly.io
  import plotly.graph_objs
  from plotly.tests.utils import TestCaseNoTemplate
label_desc: Use image node_id 15 for calling the TemplateTest obj's underlying member method code with example usage: obj.test_template_default_override() without return types