title: Write in parcer nullable value in kotlin
body: <p>Backend returns nullable <strong>Int?</strong>
  How should I write nullable value?</p>
  
  <pre><code> date class Foo (var value: Int?){
     constructor(source: Parcel) : this(
       source.readInt()
     )
  
     override fun writeToParcel(dest: Parcel, flags: Int) {
       dest.writeInt(value) // doesn't compile - writeInt expect no null value
     }
   }
  </code></pre>
  
  <p>Now I got solution:</p>
  
  <pre><code>dest.writeInt(value?: -1)
  </code></pre>
  
  <p>And then check to -1</p>
  
  <p>or write Int like string and then use value of...</p>
  
  <p>but I think it's ugly and wrong.</p>
  
  <p><strong>RESOLVED! My answer:</strong></p>
  
  <pre><code>source.readValue(Int::class.java.classLoader) as Int?,
  dest.writeValue(value)
  </code></pre>