function XMLHttpRequestBreak(fun=()=>false){
let f = XMLHttpRequest.prototype.open; let add = function(){
XMLHttpRequest.prototype.open = function(...args){
check = fun(args);
if(check){
throw check;
}
f.apply(this,args)
}
}; let remove = function(){
XMLHttpRequest.prototype.open = f
}; return {add, remove}
} test = XMLHttpRequestBreak();
test.add()
test.remove() test = XMLHttpRequestBreak(()=>"123");
test.add()
test.remove() test = XMLHttpRequestBreak(console.log);
test.add()
test.remove()