code: def assertS_IS(self, name, mode):
      # test format, lstrip is for S_IFIFO
      fmt = getattr(self.statmod, "S_IF" + name.lstrip("F"))
      self.assertEqual(self.statmod.S_IFMT(mode), fmt)
      # test that just one function returns true
      testname = "S_IS" + name
      for funcname in self.format_funcs:
          func = getattr(self.statmod, funcname, None)
          if func is None:
              if funcname == testname:
                  raise ValueError(funcname)
              continue
          if funcname == testname:
              self.assertTrue(func(mode))
          else:
              self.assertFalse(func(mode))
  
imports: import unittest
  import os
  import socket
  import sys
  from test.support import os_helper
  from test.support import socket_helper
  from test.support.import_helper import import_fresh_module
  from test.support.os_helper import TESTFN
label_desc: Use image node_id 3 for calling the TestFilemode obj's underlying member method code with example usage: obj.assertS_IS(name, mode) without return types