public static function is_same(string $file1, string $file2, $strict = false){
    if ( !is_file($file1) || !is_file($file2) ){
      throw Exception("Boo! One of the files given to the x::is_same function doesn't exist");
    }
    else{
      $same = filesize($file1) === filesize($file2);
      if ( !$strict || !$same ){
        return $same;
      }
      return filemtime($file1) === filemtime($file2);
    }
  }