an> hasAttribute(name)</h3>
<p>Returns <code>true</code> if this object has an attribute with the name specified by the string <code>name</code>.</p>
</div>
<div id="isnull" class="section level3" number="18.1.7">
<h3><span class="header-section-number">18.1.7</span> isNULL()</h3>
<p>Returns true if this object is <code>NULL</code>.</p>
</div>
<div id="sexp_type" class="section level3" number="18.1.8">
<h3><span class="header-section-number">18.1.8</span> sexp_type()</h3>
<p>Returns <code>SXPTYPE</code> of 