code: def scroll_half_page_up(event: E) -> None:
      """
      Same as ControlB, but only scroll half a page.
      """
      scroll_backward(event, half=True)
  
file_path: catboost/contrib/python/prompt-toolkit/py3/prompt_toolkit/key_binding/bindings/scroll.py
imports: from __future__ import annotations
  from prompt_toolkit.key_binding.key_processor import KeyPressEvent
label_desc: Use image node_id 4 for calling a global function with example usage: scroll_half_page_up(event) without return types