changed method invocation of 'diff' to match that of 'innerJoin' and 'leftJoin' from VertexRDD[VD] to RDD[(VertexId, VD)]

Author: Brennon York

graphx/src/main/scala/org/apache/spark/graphx/VertexRDD.scala

@@ -124,8 +124,10 @@ abstract class VertexRDD[VD](
   /**
    * Hides vertices that are the same between `this` and `other`; for vertices that are different,
    * keeps the values from `other`.
+   *
+   * @param other the other VertexRDD with which to diff.
    */
-  def diff(other: VertexRDD[VD]): VertexRDD[VD]
+  def diff(other: RDD[(VertexId, VD)]): VertexRDD[VD]
 
   /**
    * Left joins this RDD with another VertexRDD with the same index. This function will fail if

graphx/src/main/scala/org/apache/spark/graphx/impl/VertexRDDImpl.scala

@@ -103,9 +103,9 @@ class VertexRDDImpl[VD] private[graphx] (
   override def mapValues[VD2: ClassTag](f: (VertexId, VD) => VD2): VertexRDD[VD2] =
     this.mapVertexPartitions(_.map(f))
 
-  override def diff(other: VertexRDD[VD]): VertexRDD[VD] = {
+  override def diff(other: RDD[(VertexId, VD)]): VertexRDD[VD] = {
     val newPartitionsRDD = partitionsRDD.zipPartitions(
-      other.partitionsRDD, preservesPartitioning = true
+      VertexRDD(other).partitionsRDD, preservesPartitioning = true
     ) { (thisIter, otherIter) =>
       val thisPart = thisIter.next()
       val otherPart = otherIter.next()