function seq(/*...functions*/) {
    var _functions = arrayMap(arguments, wrapAsync);
    return function(/*...args*/) {
        var args = slice(arguments);
        var that = this;

        var cb = args[args.length - 1];
        if (typeof cb == 'function') {
            args.pop();
        } else {
            cb = noop;
        }

        reduce(_functions, args, function(newargs, fn, cb) {
            fn.apply(that, newargs.concat(function(err/*, ...nextargs*/) {
                var nextargs = slice(arguments, 1);
                cb(err, nextargs);
            }));
        },
        function(err, results) {
            cb.apply(that, [err].concat(results));
        });
    };
}
Version of the compose function that is more natural to read. Each function
consumes the return value of the previous function. It is the equivalent of
[compose]{@link module:ControlFlow.compose} with the arguments reversed.

Each function is executed with the `this` binding of the composed function.

@name seq
@static
@memberOf module:ControlFlow
@method
@see [async.compose]{@link module:ControlFlow.compose}
@category Control Flow
@param {...AsyncFunction} functions - the asynchronous functions to compose
@returns {Function} a function that composes the `functions` in order
@example

// Requires lodash (or underscore), express3 and dresende's orm2.
// Part of an app, that fetches cats of the logged user.
// This example uses `seq` function to avoid overnesting and error
// handling clutter.
app.get('/cats', function(request, response) {
    var User = request.models.User;
    async.seq(
        _.bind(User.get, User),  // 'User.get' has signature (id, callback(err, data))
        function(user, fn) {
            user.getCats(fn);      // 'getCats' has signature (callback(err, data))
        }
    )(req.session.user_id, function (err, cats) {
        if (err) {
            console.error(err);
            response.json({ status: 'error', message: err.message });
        } else {
            response.json({ status: 'ok', message: 'Cats found', data: cats });
        }
    });
});