{"ast_node_type":"variable","tokens":[{"end":50,"kind":"keyword","start":0,"text":"let"}]}
        let endings = self.vfs.read().1[&file_id];
    pub(crate) fn file_line_index(&self, file_id: FileId) -> Cancellable<LineIndex> {
        let index = self.analysis.file_line_index(file_id)?;