/**
 * Returns a function that when called, calls-back with the values provided.
 * Useful as the first function in a [`waterfall`]{@link module:ControlFlow.waterfall}, or for plugging values in to
 * [`auto`]{@link module:ControlFlow.auto}.
 *
 * @name constant
 * @static
 * @memberOf module:Utils
 * @method
 * @category Util
 * @param {...*} arguments... - Any number of arguments to automatically invoke
 * callback with.
 * @returns {AsyncFunction} Returns a function that when invoked, automatically
 * invokes the callback with the previous given arguments.
 * @example
 *
 * async.waterfall([
 *     async.constant(42),
 *     function (value, next) {
 *         // value === 42
 *     },
 *     //...
 * ], callback);
 *
 * async.waterfall([
 *     async.constant(filename, "utf8"),
 *     fs.readFile,
 *     function (fileData, next) {
 *         //...
 *     }
 *     //...
 * ], callback);
 *
 * async.auto({
 *     hostname: async.constant("https://server.net/"),
 *     port: findFreePort,
 *     launchServer: ["hostname", "port", function (options, cb) {
 *         startServer(options, cb);
 *     }],
 *     //...
 * }, callback);
 */
export default function(...args) {
    return function (...ignoredArgs/*, callback*/) {
        var callback = ignoredArgs.pop();
        return callback(null, ...args);
    };
}