added no args constructor

Author: Nitish1814

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

@@ -25,6 +25,9 @@ public abstract class StopWordsRemover<S,D,R,C,T> implements ISingleFieldPreproc
 	protected IContext<S,D,R,C,T> context;
     protected FieldDefinition fd;
 
+	public StopWordsRemover(){
+	}
+
 	public StopWordsRemover(IContext<S, D, R, C, T> context) {
 		this.context = context;
 	}

spark/core/src/main/java/zingg/spark/core/preprocess/stopwords/SparkStopWordsRemover.java

@@ -29,6 +29,9 @@ public class SparkStopWordsRemover extends StopWordsRemover<SparkSession,Dataset
 
 	private String udfName;
 
+	public SparkStopWordsRemover(){
+    }
+
 	public SparkStopWordsRemover(IContext<SparkSession, Dataset<Row>, Row, Column,DataType> context) {
 		super(context);
 		registerUDF();