code: def _EnsureFileExists(self):
          
          if not os.path.exists(self._filename):
              old_umask = os.umask(0o177)
              try:
                  open(self._filename, 'a+b').close()
              except OSError:
                  return False
              finally:
                  os.umask(old_umask)
          return True
docs: Touches a file; returns False on error, True on success.