ode>0 &lt;= start &lt;= end &lt;= len</code>, where
<code>len</code> is this list's <code>length</code>. The range starts at <code>start</code> and has length
<code>end - start</code>. An empty range (with <code>end == start</code>) is valid.</p>
<p>Throws an <a href="dart-core/UnsupportedError-class.html">UnsupportedError</a> if this is a fixed-length list. In that case
the list is not modified.</p>
    </section>
    
    <section class="summary source-code" id="source">
      <h2><span>Implementation</sp