function asyncLoop(iterations, func, callback) {
    var index = 0;
    var done = false;
    var loop = {
        next: function() {
            if (done) {
                //Return nothing if you call loop.next when loop is finished.
                return;
            }
            if (index < iterations) {
                index++;
                func(loop);
            } else {
                done = true;
                callback();
            }
        },
        iteration: function() {
            return index - 1;
        },
        break: function() {
            //If one query fails you want to prematurely stop the for loop and inform the client.
            done = true;
            callback();
        }
    };
    loop.next();
    return loop;
}