diff --git a/dhp-workflows/dhp-graph-mapper/src/main/java/eu/dnetlib/dhp/oa/graph/merge/MergeGraphSparkJob.java b/dhp-workflows/dhp-graph-mapper/src/main/java/eu/dnetlib/dhp/oa/graph/merge/MergeGraphSparkJob.java
index d33b9e846..8baa469bf 100644
--- a/dhp-workflows/dhp-graph-mapper/src/main/java/eu/dnetlib/dhp/oa/graph/merge/MergeGraphSparkJob.java
+++ b/dhp-workflows/dhp-graph-mapper/src/main/java/eu/dnetlib/dhp/oa/graph/merge/MergeGraphSparkJob.java
@@ -1,11 +1,11 @@
+
 package eu.dnetlib.dhp.oa.graph.merge;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
-import eu.dnetlib.dhp.application.ArgumentApplicationParser;
-import eu.dnetlib.dhp.common.HdfsSupport;
-import eu.dnetlib.dhp.oa.graph.clean.CleanGraphSparkJob;
-import eu.dnetlib.dhp.schema.common.ModelSupport;
-import eu.dnetlib.dhp.schema.oaf.*;
+import static eu.dnetlib.dhp.common.SparkSessionSupport.runWithSparkSession;
+
+import java.util.Objects;
+import java.util.Optional;
+
 import org.apache.commons.io.IOUtils;
 import org.apache.spark.SparkConf;
 import org.apache.spark.api.java.function.FilterFunction;
@@ -16,13 +16,16 @@ import org.apache.spark.sql.SaveMode;
 import org.apache.spark.sql.SparkSession;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import eu.dnetlib.dhp.application.ArgumentApplicationParser;
+import eu.dnetlib.dhp.common.HdfsSupport;
+import eu.dnetlib.dhp.oa.graph.clean.CleanGraphSparkJob;
+import eu.dnetlib.dhp.schema.common.ModelSupport;
+import eu.dnetlib.dhp.schema.oaf.*;
 import scala.Tuple2;
 
-import java.util.Objects;
-import java.util.Optional;
-
-import static eu.dnetlib.dhp.common.SparkSessionSupport.runWithSparkSession;
-
 /**
  * Combines the content from two aggregator graph tables of the same type, entities (or relationships) with the same ids
  * are picked preferring those from the BETA aggregator rather then from PROD. The identity of a relationship is defined
@@ -30,101 +33,102 @@ import static eu.dnetlib.dhp.common.SparkSessionSupport.runWithSparkSession;
  */
 public class MergeGraphSparkJob {
 
-    private static final Logger log = LoggerFactory.getLogger(CleanGraphSparkJob.class);
+	private static final Logger log = LoggerFactory.getLogger(CleanGraphSparkJob.class);
 
-    private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
+	private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
 
-    public static void main(String[] args) throws Exception {
+	public static void main(String[] args) throws Exception {
 
-        String jsonConfiguration = IOUtils
-                .toString(
-                        CleanGraphSparkJob.class
-                                .getResourceAsStream(
-                                        "/eu/dnetlib/dhp/oa/graph/merge_graphs_parameters.json"));
-        final ArgumentApplicationParser parser = new ArgumentApplicationParser(jsonConfiguration);
-        parser.parseArgument(args);
+		String jsonConfiguration = IOUtils
+			.toString(
+				CleanGraphSparkJob.class
+					.getResourceAsStream(
+						"/eu/dnetlib/dhp/oa/graph/merge_graphs_parameters.json"));
+		final ArgumentApplicationParser parser = new ArgumentApplicationParser(jsonConfiguration);
+		parser.parseArgument(args);
 
-        Boolean isSparkSessionManaged = Optional
-                .ofNullable(parser.get("isSparkSessionManaged"))
-                .map(Boolean::valueOf)
-                .orElse(Boolean.TRUE);
-        log.info("isSparkSessionManaged: {}", isSparkSessionManaged);
+		Boolean isSparkSessionManaged = Optional
+			.ofNullable(parser.get("isSparkSessionManaged"))
+			.map(Boolean::valueOf)
+			.orElse(Boolean.TRUE);
+		log.info("isSparkSessionManaged: {}", isSparkSessionManaged);
 
-        String betaInputPath = parser.get("betaInputPath");
-        log.info("betaInputPath: {}", betaInputPath);
+		String betaInputPath = parser.get("betaInputPath");
+		log.info("betaInputPath: {}", betaInputPath);
 
-        String prodInputPath = parser.get("prodInputPath");
-        log.info("prodInputPath: {}", prodInputPath);
+		String prodInputPath = parser.get("prodInputPath");
+		log.info("prodInputPath: {}", prodInputPath);
 
-        String outputPath = parser.get("outputPath");
-        log.info("outputPath: {}", outputPath);
+		String outputPath = parser.get("outputPath");
+		log.info("outputPath: {}", outputPath);
 
-        String graphTableClassName = parser.get("graphTableClassName");
-        log.info("graphTableClassName: {}", graphTableClassName);
+		String graphTableClassName = parser.get("graphTableClassName");
+		log.info("graphTableClassName: {}", graphTableClassName);
 
-        Class<? extends OafEntity> entityClazz = (Class<? extends OafEntity>) Class.forName(graphTableClassName);
+		Class<? extends OafEntity> entityClazz = (Class<? extends OafEntity>) Class.forName(graphTableClassName);
 
-        SparkConf conf = new SparkConf();
-        conf.set("spark.serializer", "org.apache.spark.serializer.KryoSerializer");
-        conf.registerKryoClasses(ModelSupport.getOafModelClasses());
+		SparkConf conf = new SparkConf();
+		conf.set("spark.serializer", "org.apache.spark.serializer.KryoSerializer");
+		conf.registerKryoClasses(ModelSupport.getOafModelClasses());
 
-        runWithSparkSession(
-                conf,
-                isSparkSessionManaged,
-                spark -> {
-                    removeOutputDir(spark, outputPath);
-                    mergeGraphTable(spark, betaInputPath, prodInputPath, entityClazz, entityClazz, outputPath);
-                });
-    }
+		runWithSparkSession(
+			conf,
+			isSparkSessionManaged,
+			spark -> {
+				removeOutputDir(spark, outputPath);
+				mergeGraphTable(spark, betaInputPath, prodInputPath, entityClazz, entityClazz, outputPath);
+			});
+	}
 
-    private static <P extends Oaf, B extends Oaf> void mergeGraphTable(
-            SparkSession spark,
-            String betaInputPath,
-            String prodInputPath,
-            Class<P> p_clazz,
-            Class<B> b_clazz,
-            String outputPath) {
+	private static <P extends Oaf, B extends Oaf> void mergeGraphTable(
+		SparkSession spark,
+		String betaInputPath,
+		String prodInputPath,
+		Class<P> p_clazz,
+		Class<B> b_clazz,
+		String outputPath) {
 
-        Dataset<Tuple2<String, B>> beta = readTableFromPath(spark, betaInputPath, b_clazz);
-        Dataset<Tuple2<String, P>> prod = readTableFromPath(spark, prodInputPath, p_clazz);
+		Dataset<Tuple2<String, B>> beta = readTableFromPath(spark, betaInputPath, b_clazz);
+		Dataset<Tuple2<String, P>> prod = readTableFromPath(spark, prodInputPath, p_clazz);
 
-        prod.joinWith(beta, prod.col("_1").equalTo(beta.col("_1")), "full_outer")
-                .map((MapFunction<Tuple2<Tuple2<String, P>, Tuple2<String, B>>, P>) value -> {
-                    Optional<P> p = Optional.ofNullable(value._1()).map(Tuple2::_2);
-                    Optional<B> b = Optional.ofNullable(value._2()).map(Tuple2::_2);
-                    if (p.isPresent() & !b.isPresent()) {
-                        return p.get();
-                    }
-                    if (b.isPresent()) {
-                        return (P) b.get();
-                    }
-                    return null;
-                }, Encoders.bean(p_clazz))
-                .filter((FilterFunction<P>) Objects::nonNull)
-                .write()
-                .mode(SaveMode.Overwrite)
-                .option("compression", "gzip")
-                .json(outputPath);
-    }
+		prod
+			.joinWith(beta, prod.col("_1").equalTo(beta.col("_1")), "full_outer")
+			.map((MapFunction<Tuple2<Tuple2<String, P>, Tuple2<String, B>>, P>) value -> {
+				Optional<P> p = Optional.ofNullable(value._1()).map(Tuple2::_2);
+				Optional<B> b = Optional.ofNullable(value._2()).map(Tuple2::_2);
+				if (p.isPresent() & !b.isPresent()) {
+					return p.get();
+				}
+				if (b.isPresent()) {
+					return (P) b.get();
+				}
+				return null;
+			}, Encoders.bean(p_clazz))
+			.filter((FilterFunction<P>) Objects::nonNull)
+			.write()
+			.mode(SaveMode.Overwrite)
+			.option("compression", "gzip")
+			.json(outputPath);
+	}
 
-     private static <T extends Oaf> Dataset<Tuple2<String, T>> readTableFromPath(
-            SparkSession spark, String inputEntityPath, Class<T> clazz) {
+	private static <T extends Oaf> Dataset<Tuple2<String, T>> readTableFromPath(
+		SparkSession spark, String inputEntityPath, Class<T> clazz) {
 
-        log.info("Reading Graph table from: {}", inputEntityPath);
-        return spark
-                .read()
-                .textFile(inputEntityPath)
-                .map(
-                        (MapFunction<String, Tuple2<String, T>>) value -> {
-                            final T t = OBJECT_MAPPER.readValue(value, clazz);
-                            final String id = ModelSupport.idFn().apply(t);
-                            return new Tuple2<>(id, t);
-                        },
-                        Encoders.tuple(Encoders.STRING(), Encoders.kryo(clazz)));
-    }
+		log.info("Reading Graph table from: {}", inputEntityPath);
+		return spark
+			.read()
+			.textFile(inputEntityPath)
+			.map(
+				(MapFunction<String, Tuple2<String, T>>) value -> {
+					final T t = OBJECT_MAPPER.readValue(value, clazz);
+					final String id = ModelSupport.idFn().apply(t);
+					return new Tuple2<>(id, t);
+				},
+				Encoders.tuple(Encoders.STRING(), Encoders.kryo(clazz)));
+	}
 
-    private static void removeOutputDir(SparkSession spark, String path) {
-        HdfsSupport.remove(path, spark.sparkContext().hadoopConfiguration());
-    }
+	private static void removeOutputDir(SparkSession spark, String path) {
+		HdfsSupport.remove(path, spark.sparkContext().hadoopConfiguration());
+	}
 
 }