code: def test_explicit_close(self):
      runner = asyncio.Runner()
      loop = runner.get_loop()
      runner.close()
      with self.assertRaisesRegex(RuntimeError, "Runner is closed"):
          runner.get_loop()
  
      self.assertTrue(loop.is_closed())
  
imports: import _thread
  import asyncio
  import contextvars
  import re
  import signal
  import sys
  import threading
  import unittest
  from test.test_asyncio import utils
  from unittest import mock
  from unittest.mock import patch
label_desc: Use image node_id 7 for calling the RunnerTests obj's underlying member method code with example usage: obj.test_explicit_close() without return types