</span>
<span class="r-in"><span><span class="co"># create problem with contiguity constraints that specify that all of</span></span></span>
<span class="r-in"><span><span class="co"># the planning units in all three of the zones must conserve first feature</span></span></span>
<span class="r-in"><span><span class="co"># in a single contiguous unit but the planning units used to conserve the</span></span></span>
<span class="r-in"><span><span class="co"># remaining features do not need to be contiguous in a