ass="optlabel">?len</span>:int <span class="arrow">&#45;&gt;</span></span>
  <span><a href="#type-transitive_callee_resolution">transitive_callee_resolution</a> <span class="arrow">&#45;&gt;</span></span>
  string</span></code></div><div class="spec-doc"><p>Serialize a value of type <a href="#type-transitive_callee_resolution"><code>transitive_callee_resolution</code></a> into a JSON string.</p><ul class="at-tags"><li class="parameter"><span class="at-tag">parameter</span> <span class="value">len</span> <p>