  DCHECK_LT(node_index, num_nodes_);</div>
<div class="line"><a name="l00154"></a><span class="lineno">  154</span>&#160;  }</div>
<div class="line"><a name="l00155"></a><span class="lineno">  155</span>&#160;  <span class="comment">// The exact number of nodes in the graph.</span></div>
<div class="line"><a name="l00156"></a><span class="lineno">  156</span>&#160;  <a class="code" href="namespaceoperations__research.html#a272bcc4d6ee0e87a7fc430a5cb13c582">NodeIndex</a> num_nodes_;</div>
<div class="line"><