{"ast_node_type":"variable","tokens":[{"end":72,"kind":"keyword","start":0,"text":"let"}]}
    let arm = wild_pat.syntax().parent().and_then(ast::MatchArm::cast)?;
    let wild_pat = ctx.find_node_at_offset_with_descend::<ast::WildcardPat>()?;
    let arm_match_expr = arm.syntax().ancestors().nth(2).and_then(ast::MatchExpr::cast)?;