function doWhilst(iteratee, test, callback) {
    callback = onlyOnce(callback || noop);
    var _iteratee = wrapAsync(iteratee);
    var next = function(err/*, ...args*/) {
        if (err) return callback(err);
        var args = slice(arguments, 1);
        if (test.apply(this, args)) return _iteratee(next);
        callback.apply(null, [null].concat(args));
    };
    _iteratee(next);
}
The post-check version of [`whilst`]{@link module:ControlFlow.whilst}. To reflect the difference in
the order of operations, the arguments `test` and `iteratee` are switched.

`doWhilst` is to `whilst` as `do while` is to `while` in plain JavaScript.

@name doWhilst
@static
@memberOf module:ControlFlow
@method
@see [async.whilst]{@link module:ControlFlow.whilst}
@category Control Flow
@param {AsyncFunction} iteratee - A function which is called each time `test`
passes. Invoked with (callback).
@param {Function} test - synchronous truth test to perform after each
execution of `iteratee`. Invoked with any non-error callback results of
`iteratee`.
@param {Function} [callback] - A callback which is called after the test
function has failed and repeated execution of `iteratee` has stopped.
`callback` will be passed an error and any arguments passed to the final
`iteratee`'s callback. Invoked with (err, [results]);