code: def test_merge_0(self):
      self.assertEqual(
          pio.templates.merge_templates(), go.layout.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 2 for calling the TestMergeTemplates obj's underlying member method code with example usage: obj.test_merge_0() without return types