def status(self):
        docs = {'updated'  : [],
                'committed': [],
                'to_commit': []}

        row = self.db.internal.find_one({'_id': 'last_sync'})

        if row and 'update' in row:
            for id in row['update']:
                docs['updated'].append(self.get(id, deleted=True))

        if row and 'commit' in row:
            for id in row['commit']:
                docs['committed'].append(self.get(id, deleted=True))

        to_commit =  self.get_docs_to_commit()
        for row in to_commit:
            doc = Document(**row)
            docs['to_commit'].append(doc)
        return docs
def __getitem__(self, index):
        """Return example at given index.

        Args:
            index(int): The index of the example to retrieve

        Returns:
            tuple: A 4-tuple with ``(img1, img2, flow, valid_flow_mask)`` where ``valid_flow_mask``
            is a numpy boolean mask of shape (H, W)
            indicating which flow values are valid. The flow is a numpy array of
            shape (2, H, W) and the images are PIL images. ``flow`` and ``valid_flow_mask`` are None if
            ``split="test"``.
        """
        return super().__getitem__(index)