{"ast_node_type":"other","tokens":[{"end":93,"kind":"keyword","start":0,"text":"//"}]}
    // The other problem is proc-macros. Proc-macros have a `Span::join` api that allows them
    // easier it gets to invalidate things again as spans are as stable as their anchor's ID.
    // to join two spans that come from the same file. rust-analyzer's proc-macro server