def get_version_delta_info(self, block_version):
        if block_version.time == -1:
            return None
        try:
            return self._dev_versions[block_version]
        except __HOLE__:
            pass

        assert block_version.time is not None
        try:
            delta = self._store.get_delta_info(block_version)
            if delta.tag == DEV:
                try:
                    ndelta = self._restapi_manager.get_version_delta_info(block_version)
                    if delta != ndelta:
                        self._store.remove_dev_references(block_version)
                        self._store.upsert_delta_info(block_version, ndelta)
                        delta = ndelta
                        if ndelta.tag == DEV:
                            self._out.info("Dev version of %s has been updated"
                                                   % str(block_version))
                except (ConnectionErrorException, NotFoundException) as e:
                    self._out.warn('You depend on DEV version "%s", but unable to '
                                           'check updates in server: %s'
                                           % (str(block_version), str(e)))
        except NotInStoreException:
            delta = self._restapi_manager.get_version_delta_info(block_version)
            if delta.tag == DEV:  # Ensure we delete the references we can have because they can be outdated
                self._store.remove_dev_references(block_version)

            self._store.upsert_delta_info(block_version, delta)

        self._dev_versions[block_version] = delta
        return delta
dataset/ETHPy150Open biicode/client/api/biiapi_proxy.py/BiiAPIProxy.get_version_delta_info