efault);
    }

    /**
     * Flatten a multi-dimensional array into a single level.
     *
     * @param  mixed[]  $array
     * @param  int  $depth
     * @return array
     */
    public static function flatten($array, $depth = INF)
    {
        return array_reduce($array, function ($result, $item) use ($depth) {
            $item = $item instanceof Collection ? $item->all() : $item;

            if (! is_array($item)) {
                return array_merge($result, [$item]);
            } elseif ($depth === 1) {
                return array_merge($result, array_values($item));
            } else {
                return array_merge($result, static::flatten($item, $depth - 1));
            }
        }, []);
    }

    /**
     * Remove one or many array items from a given array using "dot" notation.
     *
     * @param  mixed[]  $array
     * @param  mixed[]|string  $keys
     * @return void
     */
    public static function forget(&$array, $keys)
    {
        $original = &$array;

        $keys = (array) $keys;

        if (count($keys) === 0) {
            return;
        }

        foreach ($keys as $key) {
            // if the exact key exists in the top-level, remove it
            if (static::exists($array, $key)) {
                unset($array[$key]);

                continue;
            }

            $parts = explode('.', $key);

            // clean up before each pass
            $array = &$original;

            while (count($parts) > 1) {
                $part = array_shift($parts);

                if (isset($array[$part]) && is_array($array[$part])) {
                    $array = &$array[$part];
                } else {
                    continue 2;
                }
            }

            unset($array[array_shift($parts)]);
        }
    }

    /**
     * Get an item from an array using "dot" notation.
     *
     * @param  \ArrayAccess<mixed>|mixed[]  $array
     * @param  string  $key
     * @param  mixed   $default
     * @return mixed
     */
    public static function get($array, $key, $default = null)
    {
        if (! static::accessible($array)) {
            return value($default);
        }

        if (is_null($key)) {
            return $array;
        }

        if (static::exists($array, $key)) {
            return $array[$key];
        }

        foreach (explode('.', $key) as $segment) {
            if (static::accessible($array) && static::exists($array, $segment)) {
                $array = $array[$segment];
            } else {
                return value($default);
            }
        }

        return $array;
    }

    /**
     * Check if an item or items exist in an array using "dot" notation.
     *
     * @param  \ArrayAccess<mixed>|mixed[]  $array
     * @param  string|mixed[]  $keys
     * @return bool
     */
    public static function has($array, $keys)
    {
        if (is_null($keys)) {
            return false;
        }

        $keys = (array) $keys;

        if (! $array) {
            return false;
        }

        if ($keys === []) {
            return false;
        }

        foreach ($keys as $key) {
            $subKeyArray = $array;

            if (static::exists($array, $key)) {
                continue;
            }

            foreach (explode('.', $key) as $segment) {
                if (static::accessible($subKeyArray) && static::exists($subKeyArray, $segment)) {
                    $subKeyArray = $subKeyArray[$segment];
                } else {
                    return false;
                }
            }
        }

        return true;
    }

    /**
     * Determines if an array is associative.
     *
     * An array is "associative" if it doesn't have sequential numerical keys beginning with zero.
     *
     * @param  mixed[]  $array
     * @return bool
     */
    public static function isAssoc(array $array)
    {
        $keys = array_keys($array);

        return array_keys($keys) !== $keys;
    }

    /**
     * Get a subset of the items from the given array.
     *
     * @param  mixed[]  $array
     * @param  mixed[]|string  $keys
     * @return array
     */
    public static function only($array, $keys)
    {
        return array_intersect_key($array, array_flip((array) $keys));
    }

    /**
     * Pluck an array of values from an array.
     *
     * @param  mixed[]  $array
     * @param  string|mixed[]  $value
     * @param  string|mixed[]|null  $key
     * @return mixed[]
     */
    public static function pluck($array, $value, $key = null)
    {
        $results = [];

        list($value, $key) = static::explodePluckParameters($value, $key);

        foreach ($array as $item) {
            $itemValue = data_get($item, $value);

            // If the key is "null", we will just append the value to the array and keep
            // looping. Otherwise we will key the array using the value of the key we
            // received from the developer. Then we'll return the final array form.
            if (is_null($key)) {
                $results[] = $itemValue;
            } else {
                $itemKey = data_get($item, $key);

                $results[$itemKey] = $itemValue;
            }
        }

        return $results;
    }

    /**
     * Explode the "value" and "key" arguments passed to "pluck".
     *
     * @param  string|mixed[]  $value
     * @param  string|mixed[]|null  $key
     * @return mixed[]
     */
    protected static function explodePluckParameters($value, $key)
    {
        $value = is_string($value) ? explode('.', $value) : $value;

        $key = is_null($key) || is_array($key) ? $key : explode('.', $key);

        return [$value, $key];
    }

    /**
     * Push an item onto the beginning of an array.
     *
     * @param  mixed[]  $array
     * @param  mixed  $value
     * @param  mixed  $key
     * @return mixed[]
     */
    public static function prepend($array, $value, $key = null)
    {
        if (is_null($key)) {
            array_unshift($array, $value);
        } else {
            $array = [$key => $value] + $array;
        }

        return $array;
    }

    /**
     * Get a value from the array, and remove it.
     *
     * @param  mixed[]   $array
     * @param  string  $key
     * @param  mixed   $default
     * @return mixed
     */
    public static function pull(&$array, $key, $default = null)
    {
        $value = static::get($array, $key, $default);

        static::forget($array, $key);

        return $value;
    }

    /**
     * Set an array item to a given value using "dot" notation.
     *
     * If no key is given to the method, the entire array will be replaced.
     *
     * @param  mixed[]   $array
     * @param  string  $key
     * @param  mixed   $value
     * @return mixed[]
     */
    public static function set(&$array, $key, $value)
    {
        if (is_null($key)) {
            return $array = $value;
        }

        $keys = explode('.', $key);

        while (count($keys) > 1) {
            $key = array_shift($keys);

            // If the key doesn't exist at this depth, we will just create an empty array
            // to hold the next value, allowing us to create the arrays to hold final
            // values at the correct depth. Then we'll keep digging into the array.
            if (! isset($array[$key]) || ! is_array($array[$key])) {
                $array[$key] = [];
            }

            $array = &$array[$key];
        }

        $array[array_shift($keys)] = $value;

        return $array;
    }

    /**
     * Sort the array using the given callback or "dot" notation.
     *
     * @param  mixed[]  $array
     * @param  callable|string  $callback
     * @return mixed[]
     */
    public static function sort($array, $callback)
    {
        return Collection::make($array)->sortBy($callback)->all();
    }

    /**
     * Recursively sort an array by keys and values.
     *
     * @param  mixed[]  $array
     * @return mixed[]
     */
    public static function sortRecursive($array)
    {
        foreach ($array as &$value) {
            if (is_array($value)) {
                $value = static::sortRecursive($value);
            }
        }

        if (static::isAssoc($array)) {
            ksort($array);
        } else {
            sort($array);
        }

        return $array;
    }

    /**
     * Filter the array using the given callback.
     *
     * @param  mixed[]  $array
     * @param  callable  $callback
     * @return mixed[]
     */
    public static function where($array, callable $callback)
    {
        return array_filter($array, $callback, ARRAY_FILTER_USE_BOTH);
    }


	/**
	 * @param mixed ...$arrays
	 *
	 * @return mixed[]|mixed[mixed]
	 */
	public static function crossJoin(...$arrays)
	{
		$results = [[]];

		foreach ($arrays as $index => $array) {
			$append = [];

			foreach ($results as $product) {
				foreach ($array as $item) {
					$product[$index] = $item;

					$append[] = $product;
				}
			}

			$results = $append;
		}

		return $results;
	}
}