n class="fl">1000</span><span class="op">)</span>, landscape <span class="op">=</span> <span class="st">"blank"</span><span class="op">)</span></span></span>
<span class="r-in"><span></span></span>
<span class="r-in"><span><span class="co"># it is possible to construct custom landscapes (islands, corridors, etc.)</span></span></span>
<span class="r-in"><span><span class="va">island1</span> <span class="op">&lt;-</span> <span class="fu"><a href="region.html">region</a></span><span class="op">(</span><span cl