title: @JvmDefault and how add compiler option
body: <p>I need to make a <code>default void</code> method in a Kotlin interface. I ran into a problem and a hint said <em>Usage of <code>@JvmDefault</code> is only allowed with <code>-Xjvm-default</code> option</em>.</p>
  
  <p>Where do I need to write this <code>Xjvm-default</code>?</p>