a>
constant.</p>
    </section>
    
    <section class="summary source-code" id="source">
      <h2><span>Implementation</span></h2>
      <pre class="language-dart"><code class="language-dart">const TextRange({
  this.start,
  this.end,
}) : assert(start != null &amp;&amp; start &gt;= -1),
      assert(end != null &amp;&amp; end &gt;= -1);</code></pre>
    </section>

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