code: def test_families(self):
      families = font.families(self.root)
      self.assertIsInstance(families, tuple)
      self.assertTrue(families)
      for family in families:
          self.assertIsInstance(family, str)
          self.assertTrue(family)
  
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 9 for calling the FontTest obj's underlying member method code with example usage: obj.test_families() without return types