[SPARK-16249][ML] Change visibility of Object ml.clustering.LDA to public for loading

## What changes were proposed in this pull request?
jira: https://issues.apache.org/jira/browse/SPARK-16249
Change visibility of Object ml.clustering.LDA to public for loading, thus users can invoke LDA.load("path").

## How was this patch tested?

existing ut and manually test for load ( saved with current code)

Author: Yuhao Yang <yuhao.yang@intel.com>
Author: Yuhao Yang <hhbyyh@gmail.com>

Closes #13941 from hhbyyh/ldapublic.

1 files changed, 6 insertions, 4 deletions

diff --git a/mllib/src/main/scala/org/apache/spark/ml/clustering/LDA.scala b/mllib/src/main/scala/org/apache/spark/ml/clustering/LDA.scala
index b333d59258..778cd0fee7 100644
--- a/mllib/src/main/scala/org/apache/spark/ml/clustering/LDA.scala
+++ b/mllib/src/main/scala/org/apache/spark/ml/clustering/LDA.scala
@@ -880,11 +880,13 @@ class LDA @Since("1.6.0") (
   }
 }
 
-
-private[clustering] object LDA extends DefaultParamsReadable[LDA] {
+@Since("2.0.0")
+object LDA extends DefaultParamsReadable[LDA] {
 
   /** Get dataset for spark.mllib LDA */
-  def getOldDataset(dataset: Dataset[_], featuresCol: String): RDD[(Long, OldVector)] = {
+  private[clustering] def getOldDataset(
+       dataset: Dataset[_],
+       featuresCol: String): RDD[(Long, OldVector)] = {
     dataset
       .withColumn("docId", monotonicallyIncreasingId())
       .select("docId", featuresCol)
@@ -894,6 +896,6 @@ private[clustering] object LDA extends DefaultParamsReadable[LDA] {
       }
   }
 
-  @Since("1.6.0")
+  @Since("2.0.0")
   override def load(path: String): LDA = super.load(path)
 }