def save(self, storage, folder=None, name=None):
        """
        This saves a `werkzeug.FileStorage` into this upload set. If the
        upload is not allowed, an `UploadNotAllowed` error will be raised.
        Otherwise, the file will be saved and its name (including the folder)
        will be returned.
        
        :param storage: The uploaded file to save.
        :param folder: The subfolder within the upload set to save to.
        :param name: The name to save the file as. If it ends with a dot, the
                     file's extension will be appended to the end. (If you
                     are using `name`, you can include the folder in the
                     `name` instead of explicitly using `folder`, i.e.
                     ``uset.save(file, name="someguy/photo_123.")``
        """
        if not isinstance(storage, FileStorage):
            raise TypeError("storage must be a werkzeug.FileStorage")
        
        if folder is None and name is not None and name in "/":
            folder, name = name.rsplit("/", 1)
        
        basename = lowercase_ext(secure_filename(storage.filename))
        if name:
            if name.endswith('.'):
                basename = name + extension(basename)
            else:
                basename = name
        
        if not self.file_allowed(storage, basename):
            raise UploadNotAllowed()
        
        if folder:
            target_folder = os.path.join(self.config.destination, folder)
        else:
            target_folder = self.config.destination
        if not os.path.exists(target_folder):
            os.makedirs(target_folder)
        if os.path.exists(os.path.join(target_folder, basename)):
            basename = self.resolve_conflict(target_folder, basename)
        
        target = os.path.join(target_folder, basename)
        storage.save(target)
        if folder:
            return posixpath.join(folder, basename)
        else:
            return basename
dataset/ETHPy150Open srusskih/flask-uploads/flaskext/uploads.py/UploadSet.save/swapped operands of `in`