<span class="punctuation">;</span>

<span class="keyword">const</span> listenerId <span class="operator">=</span> metrics<span class="punctuation">.</span><span class="function"><a href="/api/metrics/interfaces/metrics/metrics/methods/listener/addmetriclistener/">addMetricListener</a></span><span class="punctuation">(</span>
  <span class="string">'highestPrice'</span><span class="punctuation">,</span>
  <span class="punctuation">(</span><span class="parameter">metrics<span class="punctuation">,</span> _met