pan>, </span> <span class="parameter" id="putIfAbsent-param-ifAbsent"><span class="type-annotation">dynamic</span> <span class="parameter-name">ifAbsent</span>()</span>)
      <div class="features">override</div>
    </section>
    <section class="desc markdown">
      <p>Look up the value of <code>key</code>, or add a new value if it isn't there.</p>
<p>Returns the value associated to <code>key</code>, if there is one.
Otherwise calls <code>ifAbsent</code> to get a new value, associates <code>key</code> to