{"ast_node_type":"variable","tokens":[{"end":77,"kind":"keyword","start":0,"text":"let"}]}
        let (signature, active_parameter) = callable_for_token(sema, token)?;
    pub fn at_token(sema: &Semantics<'db, RootDatabase>, token: SyntaxToken) -> Option<Self> {
        Self::from_signature_and_active_parameter(sema, signature, active_parameter)