n>):<a class="type" title="Bool - The standard Boolean type, which can either be true or false." href="../Bool.html">Bool</a></code></h3><div class="doc"><p></p></div></div><div class="field "><a name="keys"></a><h3 class="anchor"><code><a href="#keys"><span class="identifier">keys</span></a>():<a class="type" title="Iterator - An Iterator is a structure that permits iteration over elements of type T." href="../Iterator.html">Iterator</a>&lt;<span class="type">K</span>&gt;</code></h3><div class="doc"><p></p