function eachDisplayContentsElementIn(document, window, callbackDo, callbackUndo){ 
var elements = [] ; 
document.body.offsetHeight; 
var all = document.querySelectorAll('*'); 
for (var i = 0; 
i < _AN_Read_length('length', all); ++i){ 
if (window.getComputedStyle(all[i]).display === "contents") { 
callbackDo(all[i]); 
elements.push(all[i]); 
} 
} 
document.body.offsetHeight; 
for (var i = 0; 
i < _AN_Read_length("length", elements); ++i)callbackUndo(elements[i]); 
document.body.offsetHeight; 
}