MAPREDUCE-7301: Expose Mini MR Cluster attribute for testing

Signed-off-by: Mingliang Liu <liuml07@apache.org>

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-jobclient/src/test/java/org/apache/hadoop/mapred/MiniMRCluster.java

@@ -270,4 +270,8 @@ public class MiniMRCluster {
     }
   }
 
+  public MiniMRClientCluster getMrClientCluster() {
+    return mrClientCluster;
+  }
+
 }

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-jobclient/src/test/java/org/apache/hadoop/mapred/MiniMRYarnClusterAdapter.java

@@ -73,4 +73,8 @@ public class MiniMRYarnClusterAdapter implements MiniMRClientCluster {
     miniMRYarnCluster.start();
   }
 
+  public MiniMRYarnCluster getMiniMRYarnCluster() {
+    return miniMRYarnCluster;
+  }
+
 }