{"ast_node_type":"variable","tokens":[{"end":63,"kind":"keyword","start":0,"text":"let"}]}
    let search_scope = SearchScope::single_file(ctx.file_id());
fn def_is_referenced_in(def: Definition, ctx: &AssistContext<'_>) -> bool {
    def.usages(&ctx.sema).in_scope(&search_scope).at_least_one()