"op">)</span> <span class="op">{</span></span>
<span>  <span class="fu"><a href="https://rdrr.io/r/base/message.html" class="external-link">message</a></span><span class="op">(</span><span class="st">"install the sf package"</span><span class="op">)</span></span>
<span>  <span class="va">dothis</span> <span class="op">&lt;-</span> <span class="cn">FALSE</span></span>
<span><span class="op">}</span></span>
<span><span class="kw">if</span> <span class="op">(</span><span class="va">dothis</span><span class="op