retryable = function (opts, task) {
    if (!task) {
        task = opts;
        opts = null;
    }
    var _task = wrapAsync(task);
    return initialParams(function (args, callback) {
        function taskFn(cb) {
            _task.apply(null, args.concat(cb));
        }

        if (opts) retry(opts, taskFn, callback);
        else retry(taskFn, callback);

    });
}
A close relative of [`retry`]{@link module:ControlFlow.retry}.  This method
wraps a task and makes it retryable, rather than immediately calling it
with retries.

@name retryable
@static
@memberOf module:ControlFlow
@method
@see [async.retry]{@link module:ControlFlow.retry}
@category Control Flow
@param {Object|number} [opts = {times: 5, interval: 0}| 5] - optional
options, exactly the same as from `retry`
@param {AsyncFunction} task - the asynchronous function to wrap.
This function will be passed any arguments passed to the returned wrapper.
Invoked with (...args, callback).
@returns {AsyncFunction} The wrapped function, which when invoked, will
retry on an error, based on the parameters specified in `opts`.
This function will accept the same parameters as `task`.
@example

async.auto({
    dep1: async.retryable(3, getFromFlakyService),
    process: ["dep1", async.retryable(3, function (results, cb) {
        maybeProcessData(results.dep1, cb);
    })]
}, callback);