class_docstr: These tests don't spawn children or hang.
code: def _mock_tcsetattr(self, fileno, opt, mode):
      self.tcsetattr_mode_setting = mode
  
imports: from test.support import verbose, reap_children
  from test.support.import_helper import import_module
  import errno
  import os
  import pty
  import tty
  import sys
  import select
  import signal
  import socket
  import io
  import unittest
  import warnings
label_desc: Use image node_id 7 for calling the SmallPtyTests obj's underlying member method code with example usage: obj._mock_tcsetattr(fileno, opt, mode) without return types