code: def test_names(self):
      self.assertRaises(RuntimeError, font.names)
      root = tkinter.Tk()
      names = font.names()
      self.assertIsInstance(names, tuple)
      self.assertTrue(names)
      for name in names:
          self.assertIsInstance(name, str)
          self.assertTrue(name)
      self.assertIn(fontname, names)
      root.destroy()
      tkinter.NoDefaultRoot()
      self.assertRaises(RuntimeError, font.names)
  
imports: import unittest
  import tkinter
  from tkinter import font
  from test.support import requires, gc_collect, ALWAYS_EQ
  from test.test_tkinter.support import AbstractTkTest, AbstractDefaultRootTest
label_desc: Use image node_id 2 for calling the DefaultRootTest obj's underlying member method code with example usage: obj.test_names() without return types