lti-line-signature">
          <span class="returntype">dynamic</span>
          <span class="name ">source</span>
          <div class="features">final</div>
        </section>
        <section class="desc markdown">
          <p>The actual source input which caused the error.</p>
<p>This is usually a <a href="../../dart-core/String-class.html">String</a>, but can be other types too.
If it is a string, parts of it may be included in the <a href="../../dart-core/FormatException/toString.html">toString</a> m