epresent the period of the element</span>
<span class="sd">    &quot;&quot;&quot;</span>

    <span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">tid</span><span class="p">:</span> <span class="nb">int</span><span class="p">,</span> <span class="n">iUtil</span><span class="p">:</span> <span class="nb">float</span><span class="p">,</span> <span class="n">rUtil</span><span class="p">:</span> <span class="nb">fl