title: What is the name of the Long class in Kotlin JNI?
body: <p>This Kotlin function</p>
  <pre><code> @JvmStatic external fun registerNativeWindowFromSurface(): Integer;
  </code></pre>
  <p>is found by with return type <code>java/lang/Integer</code> but when I add a Long:</p>
  <pre><code> @JvmStatic external fun registerNativeWindowFromSurface(id: Long): Integer;
  </code></pre>
  <p>I cannot find it with <code>java/lang/Long</code> in the argument.</p>
  <p>Is Kotlin's Long a java <code>long</code> or a <code>java/lang/Long</code>? How can I get a Long class?</p>