code: def test_emacs_kill_ring():
      operations = (
          # abc ControlA ControlK
          "abc\x01\x0b"
          # def ControlA ControlK
          "def\x01\x0b"
          # ghi ControlA ControlK
          "ghi\x01\x0b"
          # ControlY (yank)
          "\x19"
      )
  
      result, cli = _feed_cli_with_input(operations + "\n")
      assert result.text == "ghi"
  
      result, cli = _feed_cli_with_input(operations + "\x1by\n")
      assert result.text == "def"
  
      result, cli = _feed_cli_with_input(operations + "\x1by\x1by\n")
      assert result.text == "abc"
  
      result, cli = _feed_cli_with_input(
          operations + "\x1by\x1by\x1by\n"
      )
      assert result.text == "ghi"
  
imports: from __future__ import unicode_literals
  from prompt_toolkit.application import Application
  from prompt_toolkit.buffer import Buffer, AcceptAction
  from prompt_toolkit.clipboard import InMemoryClipboard, ClipboardData
  from prompt_toolkit.enums import DEFAULT_BUFFER, EditingMode
  from prompt_toolkit.eventloop.posix import PosixEventLoop
  from prompt_toolkit.history import InMemoryHistory
  from prompt_toolkit.input import PipeInput
  from prompt_toolkit.interface import CommandLineInterface
  from prompt_toolkit.key_binding.manager import KeyBindingManager
  from prompt_toolkit.output import DummyOutput
  from prompt_toolkit.terminal.vt100_input import ANSI_SEQUENCES
  from functools import partial
  import pytest
label_desc: Use image node_id 14 for calling a global function with example usage: test_emacs_kill_ring() without return types