diff --git a/dhp-schemas/pom.xml b/dhp-schemas/pom.xml
index d8873d33d..89e52858b 100644
--- a/dhp-schemas/pom.xml
+++ b/dhp-schemas/pom.xml
@@ -30,6 +30,12 @@
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-databind</artifactId>
         </dependency>
+        
+         <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>${junit.version}</version>
+        </dependency>
 
         <dependency>
             <groupId>eu.dnetlib.dhp</groupId>
diff --git a/dhp-schemas/src/main/java/eu/dnetlib/dhp/schema/oaf/Relation.java b/dhp-schemas/src/main/java/eu/dnetlib/dhp/schema/oaf/Relation.java
index d404981f4..24a363bec 100644
--- a/dhp-schemas/src/main/java/eu/dnetlib/dhp/schema/oaf/Relation.java
+++ b/dhp-schemas/src/main/java/eu/dnetlib/dhp/schema/oaf/Relation.java
@@ -1,86 +1,83 @@
 package eu.dnetlib.dhp.schema.oaf;
 
-import org.junit.Assert;
-
 import java.util.ArrayList;
 import java.util.List;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import org.junit.Assert;
+
 public class Relation extends Oaf {
 
-    private String relType;
+	private String relType;
 
-    private String subRelType;
+	private String subRelType;
 
-    private String relClass;
+	private String relClass;
 
-    private String source;
+	private String source;
 
-    private String target;
+	private String target;
 
-    private List<KeyValue> collectedFrom = new ArrayList<>();
+	private List<KeyValue> collectedFrom = new ArrayList<>();
 
-    public String getRelType() {
-        return relType;
-    }
+	public String getRelType() {
+		return relType;
+	}
 
-    public void setRelType(String relType) {
-        this.relType = relType;
-    }
+	public void setRelType(final String relType) {
+		this.relType = relType;
+	}
 
-    public String getSubRelType() {
-        return subRelType;
-    }
+	public String getSubRelType() {
+		return subRelType;
+	}
 
-    public void setSubRelType(String subRelType) {
-        this.subRelType = subRelType;
-    }
+	public void setSubRelType(final String subRelType) {
+		this.subRelType = subRelType;
+	}
 
-    public String getRelClass() {
-        return relClass;
-    }
+	public String getRelClass() {
+		return relClass;
+	}
 
-    public void setRelClass(String relClass) {
-        this.relClass = relClass;
-    }
+	public void setRelClass(final String relClass) {
+		this.relClass = relClass;
+	}
 
-    public String getSource() {
-        return source;
-    }
+	public String getSource() {
+		return source;
+	}
 
-    public void setSource(String source) {
-        this.source = source;
-    }
+	public void setSource(final String source) {
+		this.source = source;
+	}
 
-    public String getTarget() {
-        return target;
-    }
+	public String getTarget() {
+		return target;
+	}
 
-    public void setTarget(String target) {
-        this.target = target;
-    }
+	public void setTarget(final String target) {
+		this.target = target;
+	}
 
-    public List<KeyValue> getCollectedFrom() {
-        return collectedFrom;
-    }
+	public List<KeyValue> getCollectedFrom() {
+		return collectedFrom;
+	}
 
-    public void setCollectedFrom(List<KeyValue> collectedFrom) {
-        this.collectedFrom = collectedFrom;
-    }
+	public void setCollectedFrom(final List<KeyValue> collectedFrom) {
+		this.collectedFrom = collectedFrom;
+	}
 
-    public void mergeFrom(final Relation r) {
-        Assert.assertEquals("source ids must be equal", getSource(), r.getSource());
-        Assert.assertEquals("target ids must be equal", getTarget(), r.getTarget());
-        Assert.assertEquals("relType(s) must be equal", getRelType(), r.getRelType());
-        Assert.assertEquals("subRelType(s) must be equal", getSubRelType(), r.getSubRelType());
-        Assert.assertEquals("relClass(es) must be equal", getRelClass(), r.getRelClass());
-        setCollectedFrom(
-            Stream.concat(
-                    getCollectedFrom().stream(),
-                    r.getCollectedFrom().stream())
-                .distinct() // relies on KeyValue.equals
-                .collect(Collectors.toList()));
-    }
+	public void mergeFrom(final Relation r) {
+		Assert.assertEquals("source ids must be equal", getSource(), r.getSource());
+		Assert.assertEquals("target ids must be equal", getTarget(), r.getTarget());
+		Assert.assertEquals("relType(s) must be equal", getRelType(), r.getRelType());
+		Assert.assertEquals("subRelType(s) must be equal", getSubRelType(), r.getSubRelType());
+		Assert.assertEquals("relClass(es) must be equal", getRelClass(), r.getRelClass());
+		setCollectedFrom(Stream.concat(getCollectedFrom().stream(), r.getCollectedFrom().stream())
+				.distinct() // relies on KeyValue.equals
+				.collect(Collectors.toList()));
+	}
 
 }
diff --git a/pom.xml b/pom.xml
index faed1db35..74003a407 100644
--- a/pom.xml
+++ b/pom.xml
@@ -76,7 +76,7 @@
 		<dependency>
 			<groupId>junit</groupId>
 			<artifactId>junit</artifactId>
-			<version>4.12</version>
+			<version>${junit.version}</version>
 			<scope>test</scope>
 		</dependency>
 
@@ -481,6 +481,7 @@
 		<dhp.jackson.version>2.9.6</dhp.jackson.version>
 		<dhp.commons.lang.version>3.5</dhp.commons.lang.version>
 		<scala.version>2.11.12</scala.version>
+		<junit.version>4.12</junit.version>
 		<mongodb.driver.version>3.4.2</mongodb.driver.version>
 	</properties>
 </project>