def METHOD_NAME(self) -> int:
    self._file_url = self._get_file_url()
    if isinstance(self._fs, fsspec.AbstractFileSystem):
        with DatasetGeoTiffFsDataAccessor.create_env_session(self._fs):
            overviews = self._get_overview_count()
    else:
        assert_true(self._fs is None, message="invalid type for fs")
    return len(overviews) + 1