class="qualifiers"></ul> <ul class="arguments">  <li class="argument">NODE</li>    <li class="argument">ATTRIBUTE</li>    <li class="argument lambda-list-keyword">&amp;REST</li>  </ul>  <a class="source-link" href="https://github.com/Shinmera/clip/blob/64eedbbf637a874080bfcd351b69ee6d58588d7f/conditions.lisp#L35">Source</a>  </header> <div class="docstring"><pre>Checks whether the given attribute is present on the node.

If it is, the attribute's value is returned.
Otherwise, an error of type MISSING-ATTRIB