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()