code: def test_invalid_with_no_lines(self):
      # The error formatting for invalid templates
      # has a special case for no data that the default
      # pattern can't trigger (always has at least '$')
      # So we craft a pattern that is always invalid
      # with no leading data.
      class MyTemplate(Template):
          pattern = r"""
                (?P<invalid>) |
                unreachable(
                  (?P<named>)   |
                  (?P<braced>)  |
                  (?P<escaped>)
                )
              """
  
      s = MyTemplate("")
      with self.assertRaises(ValueError) as err:
          s.substitute({})
      self.assertIn("line 1, col 1", str(err.exception))
  
imports: import unittest
  import string
  from string import Template
label_desc: Use image node_id 18 for calling the TestTemplate obj's underlying member method code with example usage: obj.test_invalid_with_no_lines() without return types