docstr: Wraps send(), sending string ``s`` to child process, with os.linesep
  automatically appended. Returns number of bytes written. 
docstr_tok: ["Wraps","send","(",")",",","sending","string","``","s","``","to","child","process",",","with","os.linesep","automatically","appended",".","Returns","number","of","bytes","written","."]
code: def sendline(self, s=""):
      """Wraps send(), sending string ``s`` to child process, with os.linesep
      automatically appended. Returns number of bytes written."""
  
      n = self.send(s)
      return n + self.send(self.linesep)
  
imports: import os
  import threading
  import subprocess
  import sys
  import time
  import signal
  import shlex
  from .spawnbase import SpawnBase, PY3
  from .exceptions import EOF
  from .utils import string_types
label_desc: Use image node_id 7 for calling the PopenSpawn obj's underlying member method code with example usage: obj.sendline(s) and returns: unknown