="r-pr">#&gt;</span> 2 6 </span>
<span class="r-out co"><span class="r-pr">#&gt;</span> </span>
<span class="r-out co"><span class="r-pr">#&gt;</span> $node_starts</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> X Y </span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 1 3 </span>
<span class="r-out co"><span class="r-pr">#&gt;</span> </span>
<span class="r-out co"><span class="r-pr">#&gt;</span> $node_ends</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> X Y </span>
<spa