TEZ-4122. TestMRRJobsDAGApi should set TezClassLoader

Signed-off-by: Jonathan Eagles <jeagles@apache.org>
diff --git a/tez-tests/src/test/java/org/apache/tez/mapreduce/TestMRRJobsDAGApi.java b/tez-tests/src/test/java/org/apache/tez/mapreduce/TestMRRJobsDAGApi.java
index a756cf9..96b7bbf 100644
--- a/tez-tests/src/test/java/org/apache/tez/mapreduce/TestMRRJobsDAGApi.java
+++ b/tez-tests/src/test/java/org/apache/tez/mapreduce/TestMRRJobsDAGApi.java
@@ -71,6 +71,7 @@
 import org.apache.tez.client.TezClient;
 import org.apache.tez.client.TezAppMasterStatus;
 import org.apache.tez.common.ReflectionUtils;
+import org.apache.tez.common.TezClassLoader;
 import org.apache.tez.common.TezUtils;
 import org.apache.tez.common.counters.FileSystemCounter;
 import org.apache.tez.common.counters.TaskCounter;
@@ -833,6 +834,7 @@
           .getConfigurationBytes());
 
       try {
+        Thread.currentThread().setContextClassLoader(TezClassLoader.getInstance());
         ReflectionUtils.getClazz(RELOCALIZATION_TEST_CLASS_NAME);
         LOG.info("Class found");
         FileSystem fs = FileSystem.get(conf);