n class='lifetime'>&#39;a</span> <span class='ident'>u32</span>) <span class='op'>-&gt;</span> <span class='kw-2'>&amp;</span><span class='lifetime'>&#39;a</span> <span class='ident'>str</span> {
    <span class='lifetime'>&#39;b</span>: {
        <span class='kw'>let</span> <span class='ident'>s</span> <span class='op'>=</span> <span class='macro'>format</span><span class='macro'>!</span>(<span class='string'>&quot;{}&quot;</span>, <span class='ident'>data</span>);
        <span class='kw'>return</span> <s