'Copy the file attached to a FileUpload to the Extension instance.
Return the file size.'

def handle_file_upload_operations(self, upload):

    upload.path = smart_path(nfd_str(upload.path))
    if private_storage.exists(self.file_path):
        raise RuntimeError(('Trying    to    upload    a    file    to    a    destination    that    already    exists:    %s' % self.file_path))
    copy_stored_file(upload.path, self.file_path, src_storage=private_storage, dst_storage=private_storage)
    return private_storage.size(self.file_path)
