const async = require('async');

var asyncFn = function (i, done) {
    if (i < 1) {
        setTimeout(done, 200);
    } else {
        setImmediate(done);
    }
};

// wrap function once, call 10 times
var timeoutFn = async.timeout(asyncFn, 100);
var j = 0;
async.whilst(
    function () {
        return j < 10;
    },
    function (done) {
        timeoutFn(j++, function (err) {
            console.log('Test 1 #' + j, err);
            done();
        });
    },
    function (err) {
    }
);