code: def test_swap_characters_before_cursor(_buffer):
      _buffer.insert_text("hello world")
      _buffer.cursor_left()
      _buffer.cursor_left()
      _buffer.swap_characters_before_cursor()
  
      assert _buffer.text == "hello wrold"
  
file_path: catboost/contrib/python/prompt-toolkit/py3/tests/test_buffer.py
imports: from __future__ import annotations
  import pytest
  from prompt_toolkit.buffer import Buffer
label_desc: Use image node_id 10 for calling a global function with example usage: test_swap_characters_before_cursor(_buffer) without return types