title: value join is not a member of org.apache.spark.rdd.RDD
body: <p>I get this error:</p>
  
  <pre><code>value join is not a member of 
      org.apache.spark.rdd.RDD[(Long, (Int, (Long, String, Array[_0])))
          forSome { type _0 &lt;: (String, Double) }]
  </code></pre>
  
  <p>The only suggestion I found is <code>import org.apache.spark.SparkContext._</code> I am already doing that.</p>
  
  <p>What am I doing wrong?</p>
  
  <p>EDIT: changing the code to eliminate <code>forSome</code> (i.e., when the object has type <code>org.apache.spark.rdd.RDD[(Long, (Int, (Long, String, Array[(String, Double)])))</code>) solved the problem.
  Is this a bug in Spark?</p>