code: def ttynames_from_env(cls, env):
      
      return tuple(env.get(cls.TTY_PATH_ENV.format(fd_id)) for fd_id in STDIO_DESCRIPTORS)
docs: Determines the ttynames for remote file descriptors (if ttys).
  
      :param dict env: A dictionary representing the environment.
      :returns: A tuple of boolean values indicating ttyname paths or None for (stdin, stdout, stderr).