object MainCode extends App {
  val conf = new SparkConf
  conf.setMaster("local[*]").setAppName(this.getClass.getName)
  val sc = new SparkContext(conf)

  // the RDD instantiation goes here
  val rdd = ...

  // instead of
  //  val thisWontWork = new ShouldBeLocal
  //  rdd.mapPartitions(_.map(thisWontWork.theMethod))
  // we'll do the following...
  rdd.mapPartitions(_.map(ShouldBeLocalWrapper.theMethodWrapper))
    // then of course some action taken
    ...

  sc.stop
}

// Creating a singleton wrapper will make the contained codes
// available to all executors. This is useful if creating ShouldBeLocal
// instance a very expensive operation. For non thread-safe, we can also
// implement object pooling of the said instance, e.g. for DB connectivities
object ShouldBeLocalWrapper {

  // Usage of ShouldBeLocal is assumed to be thread-safe.
  lazy val inst: ShouldBeLocal = new ShouldBeLocal

  // Let's say we need to use an arbitary class/object ShouldBeLocal
  // with function/method theMethod to parse the data..
  def theMethodWrapper(s: String) = inst.theMethod(s)
}