{"ast_node_type":"other","tokens":[{"end":53,"kind":"keyword","start":0,"text":"FnTrait::FnMut"}]}
            FnTrait::FnMut | FnTrait::AsyncFnMut => {
            FnTrait::FnOnce | FnTrait::AsyncFnOnce => (),
                if let TyKind::Ref(Mutability::Mut, lt, inner) = derefed_callee.kind(Interner) {