diff --git a/Cake/ORM/BufferedResultSet.php b/Cake/ORM/BufferedResultSet.php
index 25aec18459c..3ac6f58f4ea 100644
--- a/Cake/ORM/BufferedResultSet.php
+++ b/Cake/ORM/BufferedResultSet.php
@@ -1,7 +1,5 @@
 <?php
 /**
- * PHP Version 5.4
- *
  * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
  * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
  *
diff --git a/Cake/Test/TestCase/Utility/CollectionTest.php b/Cake/Test/TestCase/Utility/CollectionTest.php
index 587d219f67b..344b11ed3c3 100644
--- a/Cake/Test/TestCase/Utility/CollectionTest.php
+++ b/Cake/Test/TestCase/Utility/CollectionTest.php
@@ -202,4 +202,19 @@ public function testContains() {
 		$this->assertFalse($collection->contains('2'));
 	}
 
+/**
+ * Tests map
+ *
+ * @return void
+ */
+	public function testMap() {
+		$items = ['a' => 1, 'b' => 2, 'c' => 3];
+		$collection = new Collection($items);
+		$map = $collection->map(function($v, $k, $it) use ($collection) {
+			$this->assertSame($collection, $it);
+			return $v * $v;
+		});
+		$this->assertInstanceOf('\Cake\Utility\Iterator\ReplaceIterator', $map);
+		$this->assertEquals(['a' => 1, 'b' => 4, 'c' => 9], iterator_to_array($map));
+	}
 }
diff --git a/Cake/Test/TestCase/Utility/Iterator/ReplaceIteratorTest.php b/Cake/Test/TestCase/Utility/Iterator/ReplaceIteratorTest.php
new file mode 100644
index 00000000000..05dfb7e3336
--- /dev/null
+++ b/Cake/Test/TestCase/Utility/Iterator/ReplaceIteratorTest.php
@@ -0,0 +1,51 @@
+<?php
+/**
+ * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
+ * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
+ *
+ * Licensed under The MIT License
+ * For full copyright and license information, please see the LICENSE.txt
+ * Redistributions of files must retain the above copyright notice.
+ *
+ * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
+ * @link          http://cakephp.org CakePHP(tm) Project
+ * @since         CakePHP(tm) v 3.0.0
+ * @license       MIT License (http://www.opensource.org/licenses/mit-license.php)
+ */
+namespace Cake\Test\TestCase\Utility\Iterator;
+
+use Cake\TestSuite\TestCase;
+use Cake\Utility\Iterator\ReplaceIterator;
+
+/**
+ * ReplaceIterator Test
+ *
+ */
+class ReplaceIteratorTest extends TestCase {
+
+/**
+ * Tests that the iterator works correctly
+ *
+ * @return void
+ */
+	public function testReplace() {
+		$items = new \ArrayIterator([1, 2, 3]);
+		$callable = $this->getMock('stdClass', ['__invoke']);
+		$callable->expects($this->at(0))
+			->method('__invoke')
+			->with(1, 0, $items)
+			->will($this->returnValue(1));
+		$callable->expects($this->at(1))
+			->method('__invoke')
+			->with(2, 1, $items)
+			->will($this->returnValue(4));
+		$callable->expects($this->at(2))
+			->method('__invoke')
+			->with(3, 2, $items)
+			->will($this->returnValue(9));
+
+		$map = new ReplaceIterator($items, $callable);
+		$this->assertEquals([1, 4, 9], iterator_to_array($map));
+	}
+
+}
diff --git a/Cake/Utility/Collection.php b/Cake/Utility/Collection.php
index 6ec80466b7e..8e8df90a4a1 100644
--- a/Cake/Utility/Collection.php
+++ b/Cake/Utility/Collection.php
@@ -16,6 +16,7 @@
 
 use ArrayIterator;
 use Cake\Utility\Iterator\FilterIterator;
+use Cake\Utility\Iterator\ReplaceIterator;
 use InvalidArgumentException;
 use IteratorIterator;
 
@@ -191,10 +192,43 @@ public function contains($value) {
 		return false;
 	}
 
+/**
+ * Creates an iterator from another iterator that will modify each of the values
+ * by converting them using a callback function.
+ */
+
+/**
+ * Returns another collection after modifying each of the values in this one using
+ * the provided callable.
+ *
+ * Each time the callback is executed it will receive the value of the element
+ * in the current iteration, the key of the element and this collection as
+ * arguments, in that order.
+ *
+ * ##Example:
+ *
+ * Getting a collection of booleans where true indicates if a person is female:
+ *
+ * {{{
+ * $collection = (new Collection($people))->filter(function($person, $key) {
+ *	return $person->sex === 'female';
+ * });
+ * }}}
+ *
+ * @param callable $c the method that will receive each of the elements and
+ * returns the new value for the key that is being iterated
+ * @return \Cake\Utility\Iterator\ReplaceIterator
+ */
+	public function map(callable $c) {
+		return new ReplaceIterator($this, $c);
+	}
+
 	public function mapReduce(callable $map, callable $reduce) {
 	}
 
+
 	public function extract($property) {
+
 	}
 
 	public function max() {
diff --git a/Cake/Utility/Iterator/FilterIterator.php b/Cake/Utility/Iterator/FilterIterator.php
index 6ee1dc6f5c9..b9ed4484636 100644
--- a/Cake/Utility/Iterator/FilterIterator.php
+++ b/Cake/Utility/Iterator/FilterIterator.php
@@ -19,7 +19,7 @@
 use Iterator;
 
 /**
- * Create a filtered iterator from another iterator. The filtering is done by
+ * Creates a filtered iterator from another iterator. The filtering is done by
  * passing a callback function to each of the elements and taking them out if
  * it does not return true.
  */
@@ -33,6 +33,8 @@ class FilterIterator extends Collection {
  * in the current iteration, the key of the element and the passed $items iterator
  * as arguments, in that order.
  *
+ * @param Iterator $items the items to be filtered
+ * @param callable $callback
  * @return void
  */
 	public function __construct(Iterator $items, callable $callback) {
diff --git a/Cake/Utility/Iterator/ReplaceIterator.php b/Cake/Utility/Iterator/ReplaceIterator.php
new file mode 100644
index 00000000000..582e06f6776
--- /dev/null
+++ b/Cake/Utility/Iterator/ReplaceIterator.php
@@ -0,0 +1,60 @@
+<?php
+/**
+ * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
+ * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
+ *
+ * Licensed under The MIT License
+ * For full copyright and license information, please see the LICENSE.txt
+ * Redistributions of files must retain the above copyright notice.
+ *
+ * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
+ * @link          http://cakephp.org CakePHP(tm) Project
+ * @since         CakePHP(tm) v 3.0.0
+ * @license       MIT License (http://www.opensource.org/licenses/mit-license.php)
+ */
+namespace Cake\Utility\Iterator;
+
+use Cake\Utility\Collection;
+
+/**
+ * Creates an iterator from another iterator that will modify each of the values
+ * by converting them using a callback function.
+ */
+class ReplaceIterator extends Collection {
+
+/**
+ * The callback function to be used to modify each of the values
+ *
+ * @var callable
+ */
+	protected $_callback;
+
+/**
+ * Creates an iterator from another iterator that will modify each of the values
+ * by converting them using a callback function.
+ *
+ * Each time the callback is executed it will receive the value of the element
+ * in the current iteration, the key of the element and the passed $items iterator
+ * as arguments, in that order.
+ *
+ * @param array|\Traversable $items the items to be filtered
+ * @param callable $callback
+ * @return void
+ */
+	public function __construct($items, callable $callback) {
+		$this->_callback = $callback;
+		parent::__construct($items);
+	}
+
+/**
+ * Returns the value returned by the callback after passing the current value in
+ * the iteration
+ *
+ * @return mixed
+ */
+	public function current() {
+		$callback = $this->_callback;
+		return $callback(parent::current(), $this->key(), $this->getInnerIterator());
+	}
+
+}