    </li>
<li class="listitem">
              <code class="computeroutput"><span class="identifier">reference_type</span></code> is
              <code class="computeroutput"><span class="identifier">State</span> <span class="keyword">const</span><span class="special">&amp;</span></code>
            </li>
<li class="listitem">
              Factory functions
              <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
                    <code cla