{"ast_node_type":"function","tokens":[{"end":40,"kind":"keyword","start":0,"text":"fn"}]}
    fn test_rename_refs_for_fn_param() {
    #[test]
        check("j", r#"fn foo(i$0 : u32) -> u32 { i }"#, r#"fn foo(j : u32) -> u32 { j }"#);