{"ast_node_type":"other","tokens":[{"end":93,"kind":"keyword","start":0,"text":"///"}]}
    /// mapping is necessary for diagnostics. When a "unnecessary feature attribute" error is
    /// attributes do (as in the current implementation, `implied_by` in `#[unstable]`), then this
    /// reported, only the `#[stable]` attribute information is available, so the map is necessary