{"ast_node_type":"other","tokens":[{"end":69,"kind":"keyword","start":0,"text":"///"}]}
    /// The `HirId` is the canonical ID for the variable being bound,
    /// A fresh binding `ref mut binding @ OPT_SUBPATTERN`.
    /// (e.g., in `Ok(x) | Err(x)`, both `x` use the same canonical ID),