public static function numLinesInSheet( $path, $sheetIndex = 0 ): int {
        $emptySheetAsArray = [
            0 => [
                0 => NULL,
            ],
        ];
        $sheetName = Excel::getSheetName($path,$sheetIndex);
        $sheetAsArray      = self::sheetToArray( $path, $sheetName );
        if ( $sheetAsArray == $emptySheetAsArray ):
            return 0;
        endif;
        return count( $sheetAsArray );
    }