added whole system from ola4doc

sys/node_modules/es6-iterator/#/chain.js

@@ -0,0 +1,40 @@
+'use strict';
+
+var setPrototypeOf = require('es5-ext/object/set-prototype-of')
+  , d              = require('d')
+  , Iterator       = require('../')
+  , validIterable  = require('../valid-iterable')
+
+  , push = Array.prototype.push
+  , defineProperties = Object.defineProperties
+  , IteratorChain;
+
+IteratorChain = function (iterators) {
+	defineProperties(this, {
+		__iterators__: d('', iterators),
+		__current__: d('w', iterators.shift())
+	});
+};
+if (setPrototypeOf) setPrototypeOf(IteratorChain, Iterator);
+
+IteratorChain.prototype = Object.create(Iterator.prototype, {
+	constructor: d(IteratorChain),
+	next: d(function () {
+		var result;
+		if (!this.__current__) return { done: true, value: undefined };
+		result = this.__current__.next();
+		while (result.done) {
+			this.__current__ = this.__iterators__.shift();
+			if (!this.__current__) return { done: true, value: undefined };
+			result = this.__current__.next();
+		}
+		return result;
+	})
+});
+
+module.exports = function () {
+	var iterators = [this];
+	push.apply(iterators, arguments);
+	iterators.forEach(validIterable);
+	return new IteratorChain(iterators);
+};