{"ast_node_type":"other","tokens":[{"end":68,"kind":"keyword","start":0,"text":"(None,"}]}
                    (None, _) => expected_kind = Some(closure_kind),
                match (expected_kind, closure_kind) {
                    (Some(FnTrait::FnMut), FnTrait::Fn) => expected_kind = Some(FnTrait::Fn),