{"ast_node_type":"variable","tokens":[{"end":45,"kind":"keyword","start":0,"text":"let"}]}
    let generics = generics(db, func.into());
fn receiver_for_self_ty(db: &dyn HirDatabase, func: FunctionId, ty: Ty) -> Option<Ty> {
    let trait_self_idx = trait_self_param_idx(db, func.into())?;