lass fields are somewhat like object properties, but they have some key
differences. They are created and assigned to every instance of the class,
meaning that instance gets a <em>unique</em> version of the field. This doesn't matter
if the field is a primitive, like a string or a number, but does matter if it's
an object or an array:</p>
<pre class="language-js line-numbers"><code class="js language-js"><span class="token keyword">class</span> <span class="token class-name">Permission</span> <span class="t