added exception

Author: Nitish1814

common/core/src/main/java/zingg/common/core/preprocess/caseNormalize/CaseNormalizer.java

@@ -52,13 +52,13 @@ public boolean isApplicable() {
     }
 
     @Override
-    public ZFrame<D, R, C> preprocess(ZFrame<D, R, C> df) throws ZinggClientException {
+    public ZFrame<D, R, C> preprocess(ZFrame<D, R, C> df) {
         try {
             LOG.info("Applying case normalization on input dataframe");
             List<String> relevantFields = getRelevantFields();
             return applyCaseNormalizer(df, relevantFields);
         } catch (Exception exception) {
-            LOG.warn("Error occurred while performing case normalization, skipping it");
+            LOG.warn("Error occurred while performing case normalization, skipping it, " + exception);
         }
         return df;
     }

common/core/src/main/java/zingg/common/core/preprocess/stopwords/StopWordsRemover.java

@@ -49,7 +49,7 @@ public boolean isApplicable(){
     }
 
     @Override
-    public ZFrame<D,R,C> preprocess(ZFrame<D,R,C> df) throws ZinggClientException{
+    public ZFrame<D,R,C> preprocess(ZFrame<D,R,C> df) throws ZinggClientException {
 		try {
 			if(isApplicable()){
 				LOG.info("Applying stopwords preprocessing on input dataframe");
@@ -60,8 +60,8 @@ public ZFrame<D,R,C> preprocess(ZFrame<D,R,C> df) throws ZinggClientException{
 				df = removeStopWordsFromDF(df, fd.getFieldName(), pattern);
 			}
 			return df;
-		} catch (Exception exception) {
-			LOG.warn("Error occurred while applying stopword preprocessing, skipping");
+		} catch (Exception | ZinggClientException exception) {
+			LOG.warn("Error occurred while applying stopword preprocessing, skipping, " + exception);
 		}
 		return df;
     }