text: "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);
  };
  