title: Is there an valid proguard rule for RxJava and FasterXML?
body: <p>Now the only problem stopping me from using kotlin in production is that I can't find a correct proguard file for it.</p>
  
  <p>What I used:</p>
  
  <blockquote>
    <p>1.Kotlin</p>
    
    <p>2.Anko</p>
    
    <p>3.Jackson-Kotlin-module</p>
  </blockquote>
  
  <p>Here's the warning message:</p>
  
  <pre><code>:app:proguardRelease
  Warning: com.fasterxml.jackson.databind.ext.DOMSerializer: can't find referenced class org.w3c.dom.bootstrap.DOMImplementationRegistry
  Warning: rx.internal.util.unsafe.BaseLinkedQueueConsumerNodeRef: can't find referenced class sun.misc.Unsafe
  Warning: rx.internal.util.unsafe.BaseLinkedQueueProducerNodeRef: can't find referenced class sun.misc.Unsafe
  Warning: rx.internal.util.unsafe.ConcurrentCircularArrayQueue: can't find referenced class sun.misc.Unsafe
  Warning: rx.internal.util.unsafe.ConcurrentSequencedCircularArrayQueue: can't find referenced class sun.misc.Unsafe
  Warning: rx.internal.util.unsafe.MpmcArrayQueueConsumerField: can't find referenced class sun.misc.Unsafe
  Warning: rx.internal.util.unsafe.MpmcArrayQueueProducerField: can't find referenced class sun.misc.Unsafe
  Warning: rx.internal.util.unsafe.MpscLinkedQueue: can't find referenced class sun.misc.Unsafe
  Warning: rx.internal.util.unsafe.SpmcArrayQueueConsumerField: can't find referenced class sun.misc.Unsafe
  Warning: rx.internal.util.unsafe.SpmcArrayQueueProducerField: can't find referenced class sun.misc.Unsafe
  Warning: rx.internal.util.unsafe.SpscArrayQueue: can't find referenced class sun.misc.Unsafe
  Warning: rx.internal.util.unsafe.UnsafeAccess: can't find referenced class sun.misc.Unsafe
  Warning: there were 41 unresolved references to classes or interfaces.
  </code></pre>