ot.html">stopifnot()</a></code> calls.</p>
<div class="sourceCode" id="cb5"><pre class="downlit sourceCode r">
<code class="sourceCode R"><span class="va">stop_if_negative4</span> <span class="op">&lt;-</span> <span class="kw">function</span><span class="op">(</span><span class="va">x</span><span class="op">)</span> <span class="op">{</span>
  <span class="fu"><a href="../reference/autograph.html">autograph</a></span><span class="op">(</span><span class="fu"><a href="https://rdrr.io/r/base/stopifnot.html">s