;

        foreach ($merged as $key => $value) {
            if (
                is_array($value) &&
                isset($defaults[$key]) &&
                is_array($defaults[$key])
            ) {
                // Recursively merge arrays
                $merged[$key] = static::mergeMissingValues(
                    $value, $defaults[$key]
                );
            } elseif (
                isset($defaults[$key]) &&
                (is_null($value) || $value === '')
            ) {
                // Replace null or empty values
                $merged[$key] = $defaults[$key];
            }
        }

        return $merged;
    }

    /**
     * Return matching items from array (similar to mysql's %LIKE%)
     * 
     * @param  string|regex $pattern
     * @param  array $array
     * @return array|false
     */
    public static function like($array, $pattern)
    {
        if (!preg_match('/^([\/#~]).*\1$/', $pattern)) {
            $pattern =  '~'. preg_quote($pattern, '~') . '~i';
        }

        return preg_grep($pattern, $array);
    }

    /**
     * Return non-matching items from array (similar to mysql's NOT %LIKE%)
     * 
     * @param  string|regex $pattern
     * @param  array $array
     * @return array|false
     */
    public static function notLike($array, $pattern)
    {
        if (!preg_match('/^([\/#~]).*\1$/', $pattern)) {
            $pattern =  '~'. preg_quote($pattern, '~') . '~i';
        }

        return preg_grep($pattern, $array, PREG_GREP_INVERT);
    }

    /**
     * Return matching starting of items from array (similar to mysql's %LIKE)
     * 
     * @param  string|regex $pattern
     * @param  array $array
     * @return array|false
     */
    public static function startsLike($array, $pattern)
    {
        if (!preg_match('/^([\/#~]).*\1$/', $pattern)) {
            $pattern =  '~^'. preg_quote($pattern, '~') . '~i';
        }

        return preg_grep($pattern, $array);
    }

    /**
     * Return non-matching starting of items from array (similar to mysql's NOT %LIKE)
     * 
     * @param  string|regex $pattern
     * @param  array $array
     * @return array|false
     */
    public static function DoesNotStartLike($array, $pattern)
    {
        if (!preg_match('/^([\/#~]).*\1$/', $pattern)) {
            $pattern = '~^(?!' . preg_quote($pattern, '~') . ')~i';
        }

        return preg_grep($pattern, $array);
    }

    /**
     * Return matching ending of items from array (similar to mysql's LIKE%)
     * 
     * @param  string|regex $pattern
     * @param  array $array
     * @return array|false
     */
    public static function endsLike($array, $pattern)
    {
        if (!preg_match('/^([\/#~]).*\1$/', $pattern)) {
            $pattern =  '~'. preg_quote($pattern, '~') . '$~i';
        }

        return preg_grep($pattern, $array);
    }

    /**
     * Return non-matching ending of items from array (similar to mysql's NOT LIKE%)
     * 
     * @param  string|regex $pattern
     * @param  array $array
     * @return array|false
     */
    public static function DoesNotEndLike($array, $pattern)
    {
        if (!preg_match('/^([\/#~]).*\1$/', $pattern)) {
            $pattern =  '~'. preg_quote($pattern, '~') . '$~i';
        }

        return preg_grep($pattern, $array, PREG_GREP_INVERT);
    }

    /**
     * Return matching items from array by keys
     * 
     * @param  string|regex $pattern
     * @param  array $array
     * @return array|false
     */
    public static function keysLike($array, $pattern)
    {
        if (!preg_match('/^([\/#~]).*\1$/', $pattern)) {
            $pattern =  '~'. preg_quote($pattern, '~') . '~i';
        }

        $values = [];
        
        $keys = preg_grep($pattern, array_keys($array));
        
        foreach ($keys as $key) {
            $values[$key] = $array[$key];
        }
        
        return $values;
    }

    /**
     * Return non-matching items from array by keys
     * 
     * @param  string|regex $pattern
     * @param  array $array
     * @return array|false
     */
    public static function keysNotLike($array, $pattern)
    {
        if (!preg_match('/^([\/#~]).*\1$/', $pattern)) {
            $pattern =  '~'. preg_quote($pattern, '~') . '~i';
        }

        $values = [];
        
        $keys = preg_grep($pattern, array_keys($array), 1);
        
        foreach ($keys as $key) {
            $values[$key] = $array[$key];
        }
        
        return $values;
    }

    /**
     * Return matching starting of items from array by keys
     * 
     * @param  string|regex $pattern
     * @param  array $array
     * @return array|false
     */
    public static function keysStartLike($array, $pattern)
    {
        if (!preg_match('/^([\/#~]).*\1$/', $pattern)) {
            $pattern =  '~^'. preg_quote($pattern, '~') . '~i';
        }

        $values = [];
        
        $keys = preg_grep($pattern, array_keys($array));
        
        foreach ($keys as $key) {
            $values[$key] = $array[$key];
        }
        
        return $values;
    }

    /**
     * Return non-matching starting of items from array by keys
     * 
     * @param  string|regex $pattern
     * @param  array $array
     * @return array|false
     */
    public static function keysDoesNotStartLike($array, $pattern)
    {
        if (!preg_match('/^([\/#~]).*\1$/', $pattern)) {
            $pattern = '~^(?!' . preg_quote($pattern, '~') . ')~i';
        }

        $values = [];
        
        $keys = preg_grep($pattern, array_keys($array));
        
        foreach ($keys as $key) {
            $values[$key] = $array[$key];
        }
        
        return $values;
    }

    /**
     * Return matching ending of items from array by keys
     * 
     * @param  string|regex $pattern
     * @param  array $array
     * @return array|false
     */
    public static function keysEndLike($array, $pattern)
    {
        if (!preg_match('/^([\/#~]).*\1$/', $pattern)) {
            $pattern =  '~'. preg_quote($pattern, '~') . '$~i';
        }

        $values = [];
        
        $keys = preg_grep($pattern, array_keys($array));
        
        foreach ($keys as $key) {
            $values[$key] = $array[$key];
        }
        
        return $values;
    }

    /**
     * Return non-matching ending of items from array by keys
     * 
     * @param  string|regex $pattern
     * @param  array $array
     * @return array|false
     */
    public static function keysDoesNotEndLike($array, $pattern)
    {
        if (!preg_match('/^([\/#~]).*\1$/', $pattern)) {
            $pattern =  '~'. preg_quote($pattern, '~') . '$~i';
        }

        $values = [];
        
        $keys = preg_grep($pattern, array_keys($array), PREG_GREP_INVERT);
        
        foreach ($keys as $key) {
            $values[$key] = $array[$key];
        }
        
        return $values;
    }

    /**
     * Insert a new item in the array at the given position.
     * 
     * @param  array $array
     * @param  int $pos
     * @param  mixed $newItem
     * @return array
     */
    public static function insertAt($array, $pos, $newItem)
    {
        if (!isset($array[$pos])) {
            $array[] = $newItem;
        } else {
            $array = array_splice($array, $pos, 0, $newItem);
        }
        
        return $array;
    }

    /**
     * Inserts an item before the specified key in the given array. If the
     * key is not found, inserts the item at the beginning of the array.
     *
     * @param  array $array
     * @param  mixed $key
     * @param  mixed $newKey
     * @param  mixed $newValue
     * @return array $newArray
     */
    public static function insertBefore($array, $key, $newKey, $newValue)
    {
        $newArray = [];
        $keyFound = false;

        foreach ($array as $k => $v) {
            if ($k === $key) {
                $newArray[$newKey] = $newValue;
                $keyFound = true;
            }
            $newArray[$k] = $v;
        }

        if (!$keyFound) {
            $newArray = [$newKey => $newValue] + $newArray;
        }

        return $newArray;
    }

    /**
     * Inserts an item after the specified key in the given array. If the
     * key is not found, inserts the item at the end of the array.
     *
     * @param  array $array
     * @param  mixed $key
     * @param  mixed $newKey
     * @param  mixed $newValue
     * @return array $newArray
     */
    public static function insertAfter($array, $key, $newKey, $newValue): array {
        $newArray = [];
        $keyFound = false;

        foreach ($array as $k => $v) {
            $newArray[$k] = $v;
            if ($k === $key) {
                $newArray[$newKey] = $newValue;
                $keyFound = true;
            }
        }

        if (!$keyFound) {
            $newArray[$newKey] = $newValue;
        }

        return $newArray;
    }

    /**
     * Tests whether at least one element in the array passes
     * the test implemented by the provided callback.
     * 
     * @param  array $array
     * @param  callable $callback
     * @return bool
     */
    public static function some($array, callable $callback)
    {
        foreach ($array as $k => $v) {
            if ($callback($v, $k, $array)) {
                return true;
            }
        }

        return false;
    }

    /**
     * Tests whether all elements in the array pass the
     * test implemented by the provided callback.
     *
     * @param  array $array
     * @param  callable $callback
     * @return bool
     */
    public static function every($array, callable $callback)
    {
        foreach ($array as $k => $v) {
            if (!$callback($v, $k, $array)) {
                return false;
            }
        }

        return true;
    }

    /**
     * Finds the first element in the array that satisfies the
     * condition implemented by the callback function.
     *
     * @param array $array
     * @param callable $callback
     * @return mixed
     */
    public static function find($array, callable $callback, $findKey = false)
    {
        foreach ($array as $k => $v) {
            if ($callback($v, $k, $array)) {
                return $findKey ? $k : $v;
            }
        }

        return null;
    }

    /**
     * Finds the first key in the array that satisfies the
     * condition implemented by the callback function.
     *
     * @param array $array
     * @param callable $callback
     * @return mixed
     */
    public static function findKey($array, callable $callback)
    {
        return static::find($array, $callback, true);
    }
}