 nested item w/ file</span></span></span>
<span class="r-in"><span><span class="va">file</span> <span class="op">&lt;-</span> <span class="fu"><a href="https://rdrr.io/r/base/system.file.html" class="external-link">system.file</a></span><span class="op">(</span><span class="st">"examples"</span>, <span class="st">"books.json"</span>, package <span class="op">=</span> <span class="st">"sbtools"</span><span class="op">)</span></span></span>
<span class="r-in"><span><span class="va">id2</span> <span class="op"