diff --git a/CHANGELOG.md b/CHANGELOG.md
index 21a815c..05a89c4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,13 +1,14 @@
 # Changelog
 
-## v0.2.3-dev
+## v0.2.3
 
-**2022-??-?? — [Diff](https://github.com/maciejczyzewski/bottomline/compare/0.2.2...0.2.3) — [Docs](https://maciejczyzewski.github.io/bottomline/)**
+**2022-03-01 — [Diff](https://github.com/maciejczyzewski/bottomline/compare/0.2.2...0.2.3) — [Docs](https://maciejczyzewski.github.io/bottomline/)**
 
 * Updates to the `__::slug()` function,
   - Optimized to be more performant when given plain, old ASCII text
   - Has a workaround for [a bug in PHP 8.1](https://github.com/php/php-src/issues/7898) that would return an empty string
-* Added `__::dropWhile`, `__::dropRight`, and `dropRightWhile`
+* Added `__::dropWhile`, `__::dropRight`, and `__::dropRightWhile`
+* Fix error in `__::mapKeys` that affected PHP 5.5
 
 ## v0.2.2
 
diff --git a/docs/_data/fxn_registry.json b/docs/_data/fxn_registry.json
index 8dbb8c5..a459013 100644
--- a/docs/_data/fxn_registry.json
+++ b/docs/_data/fxn_registry.json
@@ -182,7 +182,12 @@
                     "type": "int"
                 }
             ],
-            "changelog": [],
+            "changelog": [
+                {
+                    "version": "0.2.3",
+                    "message": "added to Bottomline"
+                }
+            ],
             "exceptions": [],
             "return": {
                 "type": "array|\\Generator",
@@ -214,7 +219,12 @@
                     "type": "\\Closure|float|int|string|bool"
                 }
             ],
-            "changelog": [],
+            "changelog": [
+                {
+                    "version": "0.2.3",
+                    "message": "added to Bottomline"
+                }
+            ],
             "exceptions": [],
             "return": {
                 "type": "array|\\Generator",
@@ -246,7 +256,12 @@
                     "type": "\\Closure|float|int|string|bool"
                 }
             ],
-            "changelog": [],
+            "changelog": [
+                {
+                    "version": "0.2.3",
+                    "message": "added to Bottomline"
+                }
+            ],
             "exceptions": [],
             "return": {
                 "type": "array|\\Generator",
diff --git a/src/__/__.php b/src/__/__.php
index d47adfc..7152b8c 100644
--- a/src/__/__.php
+++ b/src/__/__.php
@@ -18,7 +18,7 @@
  ** Sequences                                                 [1]
 
  *****************************************************************
- * bottomline v0.2.1                                             *
+ * bottomline v0.2.3                                             *
  * bottomline is licensed under the MIT license                  *
  * Copyright (c) 2014 Maciej A. Czyzewski                        *
  *****************************************************************/
@@ -33,9 +33,9 @@
  * @method static array|\Generator chunk(iterable $iterable, int $size = 1, bool $preserveKeys = false) <p>Creates an array of elements split into groups the length of <code>$size</code>.</p><br><p>If array can't be split evenly, the final chunk will be the remaining elements. When <code>$preserveKeys</code> is set to TRUE, keys will be preserved. Default is FALSE, which will reindex the chunk numerically.</p> <p><strong>Usage</strong></p> <pre><code class="language-php">__::chunk([1, 2, 3, 4, 5], 3);</code></pre> <p><strong>Result</strong></p> <pre><code>[[1, 2, 3], [4, 5]]</code></pre><h2>Changelog</h2><ul><li><p><code>0.2.0</code> - iterable objects are now supported</p></li></ul><h2>Exceptions</h2><ul><li><p><code>\InvalidArgumentException</code> - when an non-array or non-traversable object is given for $iterable.</p></li><li><p><code>\Exception</code> - when an <code>\IteratorAggregate</code> is given and <code>getIterator()</code> throws an exception.</p></li></ul><h2>Returns</h2><p>When given a <code>\Traversable</code> object for <code>$iterable</code>, a generator will be returned. Otherwise, an array will be returned.</p>
  * @method static array|\Generator compact(iterable $iterable) <p>Creates an array with all falsey values removed.</p><br><p>The following values are considered falsey:</p> <ul> <li><code>false</code></li> <li><code>null</code></li> <li><code>0</code></li> <li><code>""</code></li> <li><code>undefined</code></li> <li><code>NaN</code></li> </ul> <p><strong>Usage</strong></p> <pre><code class="language-php">__::compact([0, 1, false, 2, '', 3]);</code></pre> <p><strong>Result</strong></p> <pre><code>[1, 2, 3]</code></pre><h2>Changelog</h2><ul><li><p><code>0.2.0</code> - iterable objects are now supported</p></li></ul>
  * @method static array|\Generator drop(iterable $input, int $number = 1) <p>Creates a slice of array with n elements dropped from the beginning.</p><br><p><strong>Usage</strong></p> <pre><code class="language-php">__::drop([0, 1, 3, 5], 2);</code></pre> <p><strong>Result</strong></p> <pre><code>[3, 5]</code></pre><h2>Changelog</h2><ul><li><p><code>0.2.0</code> - iterable objects are now supported</p></li></ul>
- * @method static array|\Generator dropRight(iterable $input, int $number = 1) <p>Creates a slice of an array with n elements dropped from the end.</p><br><p>If the provided iterator is an array, then an array will be returned. Otherwise, a Generator will be returned. In this latter case, the entire iterable will be buffered in memory. If the iterable contains many elements, then this could cause memory issues.</p> <p><strong>Usage</strong></p> <pre><code class="language-php">__::dropRight([0, 1, 3, 5], 2);</code></pre> <p><strong>Result</strong></p> <pre><code class="language-php">[0, 1]</code></pre><h2>Returns</h2><p>An array containing a subset of the input array with front items matching the condition removed. If the provided iterable is not an array, then a Generator will be returned.</p>
- * @method static array|\Generator dropRightWhile(iterable $input, \Closure|float|int|string|bool $condition) <p>Creates a slice of the provided array with all elements matching the condition removed from the end.</p><br><p>If the provided iterator is an array, then an array will be returned. Otherwise, a Generator will be returned. In this latter case, the entire iterable will be buffered in memory. If the iterable contains many elements, then this could cause memory issues.</p> <p><strong>Drop by Primitive Condition</strong></p> <pre><code class="language-php">__::dropRightWhile([1, 2, 3, 3], 3);</code></pre> <p><strong>Result</strong></p> <pre><code class="language-php">[1, 2]</code></pre> <p><strong>Drop by Callback</strong></p> <pre><code class="language-php">__::dropRightWhile([1, 2, 3, 4, 5], static function ($item) {<br />     return $item &gt; 3;<br /> });</code></pre> <p><strong>Result</strong></p> <pre><code class="language-php">[1, 2, 3]</code></pre><h2>Returns</h2><p>An array containing a subset of the input array with front items matching the condition removed. If the provided iterable is not an array, then a Generator will be returned.</p>
- * @method static array|\Generator dropWhile(array|iterable $input, \Closure|float|int|string|bool $condition) <p>Creates a slice of the provided array with all elements matching the condition removed from the front.</p><br><p><strong>Drop by Primitive Condition</strong></p> <pre><code class="language-php">__::dropWhile([1, 1, 2, 3, 4], 1);</code></pre> <p><strong>Result</strong></p> <pre><code class="language-php">[2, 3, 4]</code></pre> <p><strong>Drop by Callback</strong></p> <pre><code class="language-php">__::dropWhile([1, 2, 3, 4, 5], static function ($item) {<br />     return $item &lt; 3;<br /> });</code></pre> <p><strong>Result</strong></p> <pre><code class="language-php">[3, 4, 5]</code></pre><h2>Returns</h2><p>An array containing a subset of the input array with front items matching the condition removed. If the input was not an array, then a \Generator will be returned.</p>
+ * @method static array|\Generator dropRight(iterable $input, int $number = 1) <p>Creates a slice of an array with n elements dropped from the end.</p><br><p>If the provided iterator is an array, then an array will be returned. Otherwise, a Generator will be returned. In this latter case, the entire iterable will be buffered in memory. If the iterable contains many elements, then this could cause memory issues.</p> <p><strong>Usage</strong></p> <pre><code class="language-php">__::dropRight([0, 1, 3, 5], 2);</code></pre> <p><strong>Result</strong></p> <pre><code class="language-php">[0, 1]</code></pre><h2>Changelog</h2><ul><li><p><code>0.2.3</code> - added to Bottomline</p></li></ul><h2>Returns</h2><p>An array containing a subset of the input array with front items matching the condition removed. If the provided iterable is not an array, then a Generator will be returned.</p>
+ * @method static array|\Generator dropRightWhile(iterable $input, \Closure|float|int|string|bool $condition) <p>Creates a slice of the provided array with all elements matching the condition removed from the end.</p><br><p>If the provided iterator is an array, then an array will be returned. Otherwise, a Generator will be returned. In this latter case, the entire iterable will be buffered in memory. If the iterable contains many elements, then this could cause memory issues.</p> <p><strong>Drop by Primitive Condition</strong></p> <pre><code class="language-php">__::dropRightWhile([1, 2, 3, 3], 3);</code></pre> <p><strong>Result</strong></p> <pre><code class="language-php">[1, 2]</code></pre> <p><strong>Drop by Callback</strong></p> <pre><code class="language-php">__::dropRightWhile([1, 2, 3, 4, 5], static function ($item) {<br />     return $item &gt; 3;<br /> });</code></pre> <p><strong>Result</strong></p> <pre><code class="language-php">[1, 2, 3]</code></pre><h2>Changelog</h2><ul><li><p><code>0.2.3</code> - added to Bottomline</p></li></ul><h2>Returns</h2><p>An array containing a subset of the input array with front items matching the condition removed. If the provided iterable is not an array, then a Generator will be returned.</p>
+ * @method static array|\Generator dropWhile(array|iterable $input, \Closure|float|int|string|bool $condition) <p>Creates a slice of the provided array with all elements matching the condition removed from the front.</p><br><p><strong>Drop by Primitive Condition</strong></p> <pre><code class="language-php">__::dropWhile([1, 1, 2, 3, 4], 1);</code></pre> <p><strong>Result</strong></p> <pre><code class="language-php">[2, 3, 4]</code></pre> <p><strong>Drop by Callback</strong></p> <pre><code class="language-php">__::dropWhile([1, 2, 3, 4, 5], static function ($item) {<br />     return $item &lt; 3;<br /> });</code></pre> <p><strong>Result</strong></p> <pre><code class="language-php">[3, 4, 5]</code></pre><h2>Changelog</h2><ul><li><p><code>0.2.3</code> - added to Bottomline</p></li></ul><h2>Returns</h2><p>An array containing a subset of the input array with front items matching the condition removed. If the input was not an array, then a \Generator will be returned.</p>
  * @method static array|\Generator flatten(iterable $iterable, bool $shallow = false) <p>Flattens a multidimensional array or iterable.</p><br><p>If <code>$shallow</code> is set to TRUE, the array will only be flattened a single level.</p> <p><strong>Usage</strong></p> <pre><code class="language-php">__::flatten([1, 2, [3, [4]]], false);</code></pre> <p><strong>Result</strong></p> <pre><code>[1, 2, 3, 4]</code></pre><h2>Changelog</h2><ul><li><p><code>0.2.0</code> - iterable objects are now supported</p></li></ul>
  * @method static array patch(array $array, array $patches, string $parent = '') <p>Patches array by xpath.</p><br><p><strong>Usage</strong></p> <pre><code class="language-php">__::patch(<br />     [<br />         'addr' =&gt; [<br />             'country' =&gt; 'US',<br />             'zip' =&gt; 12345<br />         ]<br />     ],<br />     [<br />         '/addr/country' =&gt; 'CA',<br />         '/addr/zip' =&gt; 54321<br />     ]<br /> );</code></pre> <p><strong>Result</strong></p> <pre><code>['addr' =&gt; ['country' =&gt; 'CA', 'zip' =&gt; 54321]]</code></pre><h2>Returns</h2><p>Returns patched array</p>
  * @method static array prepend(array $array, mixed $value = null) <p>Prepend item or value to an array.</p><br><p><strong>Usage</strong></p> <pre><code class="language-php">__::prepend([1, 2, 3], 4);</code></pre> <p><strong>Result</strong></p> <pre><code>[4, 1, 2, 3]</code></pre>
diff --git a/src/__/arrays/dropRight.php b/src/__/arrays/dropRight.php
index e13df98..fbb4cb5 100644
--- a/src/__/arrays/dropRight.php
+++ b/src/__/arrays/dropRight.php
@@ -64,6 +64,8 @@ function dropRightArray($input, $number)
  * @see dropWhile
  * @see dropRightWhile
  *
+ * @since 0.2.3 added to Bottomline
+ *
  * @return array|\Generator An array containing a subset of the input array with front items matching the condition
  * removed. If the provided iterable is not an array, then a Generator will be returned.
  */
diff --git a/src/__/arrays/dropRightWhile.php b/src/__/arrays/dropRightWhile.php
index f5e1caa..caa4fbf 100644
--- a/src/__/arrays/dropRightWhile.php
+++ b/src/__/arrays/dropRightWhile.php
@@ -87,6 +87,8 @@ function dropArrayRightWhile($input, $comparison)
  * @see dropRight
  * @see dropRightWhile
  *
+ * @since 0.2.3 added to Bottomline
+ *
  * @return array|\Generator An array containing a subset of the input array with front items matching the condition
  * removed. If the provided iterable is not an array, then a Generator will be returned.
  */
diff --git a/src/__/arrays/dropWhile.php b/src/__/arrays/dropWhile.php
index 81d4af4..94c64a6 100644
--- a/src/__/arrays/dropWhile.php
+++ b/src/__/arrays/dropWhile.php
@@ -91,6 +91,8 @@ function dropArrayWhile($input, $comparison)
  * @see dropRight
  * @see dropRightWhile
  *
+ * @since 0.2.3 added to Bottomline
+ *
  * @return array|\Generator An array containing a subset of the input array with front
  * items matching the condition removed. If the input was not an array, then a \Generator
  * will be returned.
diff --git a/src/__/sequences/BottomlineWrapper.php b/src/__/sequences/BottomlineWrapper.php
index ad5faf5..689330d 100644
--- a/src/__/sequences/BottomlineWrapper.php
+++ b/src/__/sequences/BottomlineWrapper.php
@@ -8,9 +8,9 @@
  * @method static \BottomlineWrapper chunk(int $size = 1, bool $preserveKeys = false) <p>Creates an array of elements split into groups the length of <code>$size</code>.</p><br><p>If array can't be split evenly, the final chunk will be the remaining elements. When <code>$preserveKeys</code> is set to TRUE, keys will be preserved. Default is FALSE, which will reindex the chunk numerically.</p> <p><strong>Usage</strong></p> <pre><code class="language-php">__::chunk([1, 2, 3, 4, 5], 3);</code></pre> <p><strong>Result</strong></p> <pre><code>[[1, 2, 3], [4, 5]]</code></pre><h2>Changelog</h2><ul><li><p><code>0.2.0</code> - iterable objects are now supported</p></li></ul><h2>Exceptions</h2><ul><li><p><code>\InvalidArgumentException</code> - when an non-array or non-traversable object is given for $iterable.</p></li><li><p><code>\Exception</code> - when an <code>\IteratorAggregate</code> is given and <code>getIterator()</code> throws an exception.</p></li></ul><h2>Returns</h2><p>When given a <code>\Traversable</code> object for <code>$iterable</code>, a generator will be returned. Otherwise, an array will be returned.</p>
  * @method static \BottomlineWrapper compact() <p>Creates an array with all falsey values removed.</p><br><p>The following values are considered falsey:</p> <ul> <li><code>false</code></li> <li><code>null</code></li> <li><code>0</code></li> <li><code>""</code></li> <li><code>undefined</code></li> <li><code>NaN</code></li> </ul> <p><strong>Usage</strong></p> <pre><code class="language-php">__::compact([0, 1, false, 2, '', 3]);</code></pre> <p><strong>Result</strong></p> <pre><code>[1, 2, 3]</code></pre><h2>Changelog</h2><ul><li><p><code>0.2.0</code> - iterable objects are now supported</p></li></ul>
  * @method static \BottomlineWrapper drop(int $number = 1) <p>Creates a slice of array with n elements dropped from the beginning.</p><br><p><strong>Usage</strong></p> <pre><code class="language-php">__::drop([0, 1, 3, 5], 2);</code></pre> <p><strong>Result</strong></p> <pre><code>[3, 5]</code></pre><h2>Changelog</h2><ul><li><p><code>0.2.0</code> - iterable objects are now supported</p></li></ul>
- * @method static \BottomlineWrapper dropRight(int $number = 1) <p>Creates a slice of an array with n elements dropped from the end.</p><br><p>If the provided iterator is an array, then an array will be returned. Otherwise, a Generator will be returned. In this latter case, the entire iterable will be buffered in memory. If the iterable contains many elements, then this could cause memory issues.</p> <p><strong>Usage</strong></p> <pre><code class="language-php">__::dropRight([0, 1, 3, 5], 2);</code></pre> <p><strong>Result</strong></p> <pre><code class="language-php">[0, 1]</code></pre><h2>Returns</h2><p>An array containing a subset of the input array with front items matching the condition removed. If the provided iterable is not an array, then a Generator will be returned.</p>
- * @method static \BottomlineWrapper dropRightWhile(\Closure|float|int|string|bool $condition) <p>Creates a slice of the provided array with all elements matching the condition removed from the end.</p><br><p>If the provided iterator is an array, then an array will be returned. Otherwise, a Generator will be returned. In this latter case, the entire iterable will be buffered in memory. If the iterable contains many elements, then this could cause memory issues.</p> <p><strong>Drop by Primitive Condition</strong></p> <pre><code class="language-php">__::dropRightWhile([1, 2, 3, 3], 3);</code></pre> <p><strong>Result</strong></p> <pre><code class="language-php">[1, 2]</code></pre> <p><strong>Drop by Callback</strong></p> <pre><code class="language-php">__::dropRightWhile([1, 2, 3, 4, 5], static function ($item) {<br />     return $item &gt; 3;<br /> });</code></pre> <p><strong>Result</strong></p> <pre><code class="language-php">[1, 2, 3]</code></pre><h2>Returns</h2><p>An array containing a subset of the input array with front items matching the condition removed. If the provided iterable is not an array, then a Generator will be returned.</p>
- * @method static \BottomlineWrapper dropWhile(\Closure|float|int|string|bool $condition) <p>Creates a slice of the provided array with all elements matching the condition removed from the front.</p><br><p><strong>Drop by Primitive Condition</strong></p> <pre><code class="language-php">__::dropWhile([1, 1, 2, 3, 4], 1);</code></pre> <p><strong>Result</strong></p> <pre><code class="language-php">[2, 3, 4]</code></pre> <p><strong>Drop by Callback</strong></p> <pre><code class="language-php">__::dropWhile([1, 2, 3, 4, 5], static function ($item) {<br />     return $item &lt; 3;<br /> });</code></pre> <p><strong>Result</strong></p> <pre><code class="language-php">[3, 4, 5]</code></pre><h2>Returns</h2><p>An array containing a subset of the input array with front items matching the condition removed. If the input was not an array, then a \Generator will be returned.</p>
+ * @method static \BottomlineWrapper dropRight(int $number = 1) <p>Creates a slice of an array with n elements dropped from the end.</p><br><p>If the provided iterator is an array, then an array will be returned. Otherwise, a Generator will be returned. In this latter case, the entire iterable will be buffered in memory. If the iterable contains many elements, then this could cause memory issues.</p> <p><strong>Usage</strong></p> <pre><code class="language-php">__::dropRight([0, 1, 3, 5], 2);</code></pre> <p><strong>Result</strong></p> <pre><code class="language-php">[0, 1]</code></pre><h2>Changelog</h2><ul><li><p><code>0.2.3</code> - added to Bottomline</p></li></ul><h2>Returns</h2><p>An array containing a subset of the input array with front items matching the condition removed. If the provided iterable is not an array, then a Generator will be returned.</p>
+ * @method static \BottomlineWrapper dropRightWhile(\Closure|float|int|string|bool $condition) <p>Creates a slice of the provided array with all elements matching the condition removed from the end.</p><br><p>If the provided iterator is an array, then an array will be returned. Otherwise, a Generator will be returned. In this latter case, the entire iterable will be buffered in memory. If the iterable contains many elements, then this could cause memory issues.</p> <p><strong>Drop by Primitive Condition</strong></p> <pre><code class="language-php">__::dropRightWhile([1, 2, 3, 3], 3);</code></pre> <p><strong>Result</strong></p> <pre><code class="language-php">[1, 2]</code></pre> <p><strong>Drop by Callback</strong></p> <pre><code class="language-php">__::dropRightWhile([1, 2, 3, 4, 5], static function ($item) {<br />     return $item &gt; 3;<br /> });</code></pre> <p><strong>Result</strong></p> <pre><code class="language-php">[1, 2, 3]</code></pre><h2>Changelog</h2><ul><li><p><code>0.2.3</code> - added to Bottomline</p></li></ul><h2>Returns</h2><p>An array containing a subset of the input array with front items matching the condition removed. If the provided iterable is not an array, then a Generator will be returned.</p>
+ * @method static \BottomlineWrapper dropWhile(\Closure|float|int|string|bool $condition) <p>Creates a slice of the provided array with all elements matching the condition removed from the front.</p><br><p><strong>Drop by Primitive Condition</strong></p> <pre><code class="language-php">__::dropWhile([1, 1, 2, 3, 4], 1);</code></pre> <p><strong>Result</strong></p> <pre><code class="language-php">[2, 3, 4]</code></pre> <p><strong>Drop by Callback</strong></p> <pre><code class="language-php">__::dropWhile([1, 2, 3, 4, 5], static function ($item) {<br />     return $item &lt; 3;<br /> });</code></pre> <p><strong>Result</strong></p> <pre><code class="language-php">[3, 4, 5]</code></pre><h2>Changelog</h2><ul><li><p><code>0.2.3</code> - added to Bottomline</p></li></ul><h2>Returns</h2><p>An array containing a subset of the input array with front items matching the condition removed. If the input was not an array, then a \Generator will be returned.</p>
  * @method static \BottomlineWrapper flatten(bool $shallow = false) <p>Flattens a multidimensional array or iterable.</p><br><p>If <code>$shallow</code> is set to TRUE, the array will only be flattened a single level.</p> <p><strong>Usage</strong></p> <pre><code class="language-php">__::flatten([1, 2, [3, [4]]], false);</code></pre> <p><strong>Result</strong></p> <pre><code>[1, 2, 3, 4]</code></pre><h2>Changelog</h2><ul><li><p><code>0.2.0</code> - iterable objects are now supported</p></li></ul>
  * @method static \BottomlineWrapper patch(array $patches, string $parent = '') <p>Patches array by xpath.</p><br><p><strong>Usage</strong></p> <pre><code class="language-php">__::patch(<br />     [<br />         'addr' =&gt; [<br />             'country' =&gt; 'US',<br />             'zip' =&gt; 12345<br />         ]<br />     ],<br />     [<br />         '/addr/country' =&gt; 'CA',<br />         '/addr/zip' =&gt; 54321<br />     ]<br /> );</code></pre> <p><strong>Result</strong></p> <pre><code>['addr' =&gt; ['country' =&gt; 'CA', 'zip' =&gt; 54321]]</code></pre><h2>Returns</h2><p>Returns patched array</p>
  * @method static \BottomlineWrapper prepend(mixed $value = null) <p>Prepend item or value to an array.</p><br><p><strong>Usage</strong></p> <pre><code class="language-php">__::prepend([1, 2, 3], 4);</code></pre> <p><strong>Result</strong></p> <pre><code>[4, 1, 2, 3]</code></pre>