title: value toDS is not a member of org.apache.spark.rdd.RDD
body: <p>I am trying to write sample Apache Spark program that converts RDD to Dataset. But in that process, I am getting compile time error.</p>
  
  <p>Here is my sample code and error:</p>
  
  <p><strong>code:</strong></p>
  
  <pre><code>import org.apache.spark.SparkConf
  import org.apache.spark.rdd.RDD
  import org.apache.spark.SparkContext
  import org.apache.spark.sql.Dataset
  
  object Hello {
  
    case class Person(name: String, age: Int)
  
    def main(args: Array[String]){
      val conf = new SparkConf()
        .setAppName("first example")
        .setMaster("local")
      val sc = new SparkContext(conf)
      val peopleRDD: RDD[Person] = sc.parallelize(Seq(Person("John", 27)))
      val people = peopleRDD.toDS
    }
  }
  </code></pre>
  
  <p><strong>and my error is:</strong></p>
  
  <pre><code>value toDS is not a member of org.apache.spark.rdd.RDD[Person]
  </code></pre>
  
  <p>I have added Spark core and spark SQL jars.</p>
  
  <p>and my versions are:</p>
  
  <p>Spark 1.6.2</p>
  
  <p>scala 2.10</p>