{"ast_node_type":"function","tokens":[{"end":62,"kind":"keyword","start":0,"text":"r#\"fn"}]}
            r#"fn foo<G>(foo: impl Foo, bar: $0impl Bar) {}"#,
            introduce_named_type_parameter,
            r#"fn foo<G, $0B: Bar>(foo: impl Foo, bar: B) {}"#,