{"ast_node_type":"other","tokens":[{"end":57,"kind":"keyword","start":0,"text":"caller_body.required_consts.as_mut().unwrap().extend("}]}
    caller_body.required_consts.as_mut().unwrap().extend(
    // because we are calling `instantiate_and_normalize_erasing_regions` -- so we filter again.
        callee_body.required_consts().into_iter().filter(|ct| ct.const_.is_required_const()),