code: def test_template_iter(self):
      self.assertIn("test_template", set(pio.templates))
  
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 19 for calling the TemplateTest obj's underlying member method code with example usage: obj.test_template_iter() without return types