des : 
  <span><span><span><a href="argument-1-Operator/Symbol/Shape/Type/index.html#type-attr">Operator.Symbol.Shape.Type.attr</a> <a href="../../Owl_graph/index.html#type-node">Owl_graph.node</a></span> array</span> <span class="arrow">&#45;&gt;</span></span>
  unit</span></code></div></div></div></body></html>
