field of a structure as optional.">@:optional</span><span class="label label-optional">optional</span><a href="#rate"><span class="identifier">rate</span></a>:<a class="type" title="Null - Null&amp;lt;T&amp;gt; is a wrapper that can be used to make the basic types Int, Float and Bool nullable on static targets." href="../../../Null.html">Null</a>&lt;<a class="type" title="Float - The standard Float type, this is a double-precision IEEE 64bit float." href="../../../Float.html">Float</a>&gt;</code></h3><div c