docs: def verify_checksum(self, progress_callback=None, chunk_size=None,
                          throws=True, checksum_kwargs=None, **kwargs):
          """Verify checksum of file instance.
  
          :param bool throws: If `True`, exceptions raised during checksum
              calculation will be re-raised after logging. If set to `False`, and
              an exception occurs, the `last_check` field is set to `None`
              (`last_check_at` of course is updated), since no check actually was
              performed.
          :param dict checksum_kwargs: Passed as `**kwargs`` to
              ``storage().checksum``.
          """
          try:
              real_checksum = self.storage(**kwargs).checksum(
                  progress_callback=progress_callback, chunk_size=chunk_size,
                  **(checksum_kwargs or {}))
          except Exception as exc:
              current_app.logger.exception(str(exc))
              if throws:
                  raise
              real_checksum = None
          with db.session.begin_nested():
              self.last_check = (None if real_checksum is None
                                 else (self.checksum == real_checksum))
              self.last_check_at = datetime.utcnow()
          return self.last_check