diff --git a/src/helper/Arr.php b/src/helper/Arr.php
index ed4d6a9..4409f8c 100644
--- a/src/helper/Arr.php
+++ b/src/helper/Arr.php
@@ -32,9 +32,9 @@ public static function accessible($value)
     /**
      * Add an element to an array using "dot" notation if it doesn't exist.
      *
-     * @param array  $array
+     * @param array $array
      * @param string $key
-     * @param mixed  $value
+     * @param mixed $value
      * @return array
      */
     public static function add($array, $key, $value)
@@ -110,7 +110,7 @@ public static function divide($array)
     /**
      * Flatten a multi-dimensional associative array with dots.
      *
-     * @param array  $array
+     * @param array $array
      * @param string $prepend
      * @return array
      */
@@ -132,7 +132,7 @@ public static function dot($array, $prepend = '')
     /**
      * Get all of the given array except for a specified array of keys.
      *
-     * @param array        $array
+     * @param array $array
      * @param array|string $keys
      * @return array
      */
@@ -147,7 +147,7 @@ public static function except($array, $keys)
      * Determine if the given key exists in the provided array.
      *
      * @param \ArrayAccess|array $array
-     * @param string|int         $key
+     * @param string|int $key
      * @return bool
      */
     public static function exists($array, $key)
@@ -162,9 +162,9 @@ public static function exists($array, $key)
     /**
      * Return the first element in an array passing a given truth test.
      *
-     * @param array         $array
+     * @param array $array
      * @param callable|null $callback
-     * @param mixed         $default
+     * @param mixed $default
      * @return mixed
      */
     public static function first($array, callable $callback = null, $default = null)
@@ -191,9 +191,9 @@ public static function first($array, callable $callback = null, $default = null)
     /**
      * Return the last element in an array passing a given truth test.
      *
-     * @param array         $array
+     * @param array $array
      * @param callable|null $callback
-     * @param mixed         $default
+     * @param mixed $default
      * @return mixed
      */
     public static function last($array, callable $callback = null, $default = null)
@@ -209,7 +209,7 @@ public static function last($array, callable $callback = null, $default = null)
      * Flatten a multi-dimensional array into a single level.
      *
      * @param array $array
-     * @param int   $depth
+     * @param int $depth
      * @return array
      */
     public static function flatten($array, $depth = INF)
@@ -234,7 +234,7 @@ public static function flatten($array, $depth = INF)
     /**
      * Remove one or many array items from a given array using "dot" notation.
      *
-     * @param array        $array
+     * @param array $array
      * @param array|string $keys
      * @return void
      */
@@ -279,8 +279,8 @@ public static function forget(&$array, $keys)
      * Get an item from an array using "dot" notation.
      *
      * @param \ArrayAccess|array $array
-     * @param string             $key
-     * @param mixed              $default
+     * @param string $key
+     * @param mixed $default
      * @return mixed
      */
     public static function get($array, $key, $default = null)
@@ -316,7 +316,7 @@ public static function get($array, $key, $default = null)
      * Check if an item or items exist in an array using "dot" notation.
      *
      * @param \ArrayAccess|array $array
-     * @param string|array       $keys
+     * @param string|array $keys
      * @return bool
      */
     public static function has($array, $keys)
@@ -364,7 +364,7 @@ public static function isAssoc(array $array)
     /**
      * Get a subset of the items from the given array.
      *
-     * @param array        $array
+     * @param array $array
      * @param array|string $keys
      * @return array
      */
@@ -376,8 +376,8 @@ public static function only($array, $keys)
     /**
      * Pluck an array of values from an array.
      *
-     * @param array             $array
-     * @param string|array      $value
+     * @param array $array
+     * @param string|array $value
      * @param string|array|null $key
      * @return array
      */
@@ -412,7 +412,7 @@ public static function pluck($array, $value, $key = null)
     /**
      * Explode the "value" and "key" arguments passed to "pluck".
      *
-     * @param string|array      $value
+     * @param string|array $value
      * @param string|array|null $key
      * @return array
      */
@@ -447,9 +447,9 @@ public static function prepend($array, $value, $key = null)
     /**
      * Get a value from the array, and remove it.
      *
-     * @param array  $array
+     * @param array $array
      * @param string $key
-     * @param mixed  $default
+     * @param mixed $default
      * @return mixed
      */
     public static function pull(&$array, $key, $default = null)
@@ -464,7 +464,7 @@ public static function pull(&$array, $key, $default = null)
     /**
      * Get one or a specified number of random values from an array.
      *
-     * @param array    $array
+     * @param array $array
      * @param int|null $number
      * @return mixed
      *
@@ -506,9 +506,9 @@ public static function random($array, $number = null)
      *
      * If no key is given to the method, the entire array will be replaced.
      *
-     * @param array  $array
+     * @param array $array
      * @param string $key
-     * @param mixed  $value
+     * @param mixed $value
      * @return array
      */
     public static function set(&$array, $key, $value)
@@ -540,7 +540,7 @@ public static function set(&$array, $key, $value)
     /**
      * Shuffle the given array and return the result.
      *
-     * @param array    $array
+     * @param array $array
      * @param int|null $seed
      * @return array
      */
@@ -562,7 +562,7 @@ public static function shuffle($array, $seed = null)
     /**
      * Sort the array using the given callback or "dot" notation.
      *
-     * @param array                $array
+     * @param array $array
      * @param callable|string|null $callback
      * @return array
      */
@@ -608,7 +608,7 @@ public static function query($array)
     /**
      * Filter the array using the given callback.
      *
-     * @param array    $array
+     * @param array $array
      * @param callable $callback
      * @return array
      */
@@ -631,4 +631,29 @@ public static function wrap($value)
 
         return is_array($value) ? $value : [$value];
     }
-}
\ No newline at end of file
+
+    public static function mergeDeep(array ...$arrays): array
+    {
+        $result = [];
+        foreach ($arrays as $array) {
+            foreach ($array as $key => $value) {
+                if (is_integer($key)) {
+                    $result[] = $value;
+                } elseif (isset($result[$key]) && is_array($result[$key]) && is_array($value)) {
+                    $result[$key] = self::mergeDeep(
+                        $result[$key],
+                        $value
+                    );
+                } else {
+                    $result[$key] = $value;
+                }
+            }
+        }
+        return $result;
+    }
+
+    public static function flatMap(callable $fn, array $array): array
+    {
+        return array_merge(...array_map($fn, $array));
+    }
+}