title: how to create PipelineRDD from Java ref type JavaRDD in SparkR?
body: <p>I'm calling some code in a jar package in SparkR that returns a Java ref type for a JavaRDD. When converting to DataFrame with <code>createDataFrame(sqlContext, myRDD)</code> I get an error</p>
  
  <pre><code>Error in createDataFrame(sqlContext, myRDD) : unexpected type: jobj
  </code></pre>
  
  <p>What's the right way to take the reference to the RDD in the backend and construct the SparkR DataFrame and use all the lovely R functions it offers?</p>