code: def scroll_page_down(event: E) -> None:
      """
      Scroll page down. (Prefer the cursor at the top of the page, after scrolling.)
      """
      w = event.app.layout.current_window
      b = event.app.current_buffer
  
      if w and w.render_info:
          # Scroll down one page.
          line_index = max(
              w.render_info.last_visible_line(), w.vertical_scroll + 1
          )
          w.vertical_scroll = line_index
  
          b.cursor_position = b.document.translate_row_col_to_index(
              line_index, 0
          )
          b.cursor_position += b.document.get_start_of_line_position(
              after_whitespace=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 7 for calling a global function with example usage: scroll_page_down(event) without return types