pub fn ui_operation(
    a: &mut ApiPieceOpArgs<'_>,
    OcculterRotationChecked,
    opname: &str,
    _wrc: WhatResponseToClientOp,
    region: &RectC<i32>
) -> Result<Option<(PieceUpdate, Vec<Box<dyn FnOnce(&'r mut PrepareUpdatesBuffer<'_>) + 'static, Global>, Global>)>, ApiPieceOpError>