code: def test_empty_input(self):
      async def empty_input():
          code = "import sys; data = sys.stdin.read(); print(len(data))"
          proc = await asyncio.create_subprocess_exec(
              sys.executable,
              "-c",
              code,
              stdin=asyncio.subprocess.PIPE,
              stdout=asyncio.subprocess.PIPE,
              stderr=asyncio.subprocess.PIPE,
              close_fds=False,
          )
          stdout, stderr = await proc.communicate(b"")
          exitcode = await proc.wait()
          return (stdout, exitcode)
  
      output, exitcode = self.loop.run_until_complete(empty_input())
      self.assertEqual(output.rstrip(), b"0")
      self.assertEqual(exitcode, 0)
  
imports: import os
  import signal
  import sys
  import textwrap
  import unittest
  import warnings
  from unittest import mock
  import asyncio
  from asyncio import base_subprocess
  from asyncio import subprocess
  from test.test_asyncio import utils
  from test import support
  from test.support import os_helper
label_desc: Use image node_id 14 for calling the SubprocessMixin obj's underlying member method code with example usage: obj.test_empty_input() and returns: stdout,  exitcode