public static function mb_str_split( $str, $split_length = 1 ) {
		// We can safely cast to an array here, as long as $str convertible to a string.
		$result = (array) \preg_split( '//u', $str , -1, PREG_SPLIT_NO_EMPTY );

		if ( $split_length > 1 ) {
			$splits = [];
			foreach ( \array_chunk( $result, $split_length ) as $chunk ) {
				$splits[] = \join( '', $chunk );
			}

			$result = $splits;
		}

		return $result;
	}