{"ast_node_type":"other","tokens":[{"end":90,"kind":"keyword","start":0,"text":"//"}]}
    // See https://github.com/rust-lang/rust/pull/69838/files#r395217057 for a discussion.
    // then the path of `bar.rs` should be relative to the directory of `file`.
    // `MacroExpander::fully_expand_fragment` later restores, so "stack discipline" is maintained.