--- a/backend/src/main/java/org/dive4elements/river/model/Annotation.java	Mon Jun 25 17:58:11 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/model/Annotation.java	Mon Jun 25 19:21:11 2018 +0200
@@ -10,15 +10,18 @@
 
 import java.io.Serializable;
 
+import javax.persistence.Column;
 import javax.persistence.Entity;
-import javax.persistence.Id;
-import javax.persistence.Table;
 import javax.persistence.GeneratedValue;
-import javax.persistence.Column;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.OneToOne;
 import javax.persistence.SequenceGenerator;
-import javax.persistence.GenerationType;
-import javax.persistence.OneToOne;
-import javax.persistence.JoinColumn;
+import javax.persistence.Table;
+import javax.persistence.Transient;
+
+import org.dive4elements.river.model.Attribute.AttributeKey;
 
 @Entity
 @Table(name = "annotations")
@@ -36,12 +39,12 @@
     }
 
     public Annotation(
-        Range          range,
-        Attribute      attribute,
-        Position       position,
-        Edge           edge,
-        AnnotationType type
-    ) {
+            final Range          range,
+            final Attribute      attribute,
+            final Position       position,
+            final Edge           edge,
+            final AnnotationType type
+            ) {
         this.range     = range;
         this.attribute = attribute;
         this.position  = position;
@@ -51,68 +54,73 @@
 
     @Id
     @SequenceGenerator(
-        name           = "SEQUENCE_ANNOTATIONS_ID_SEQ",
-        sequenceName   = "ANNOTATIONS_ID_SEQ",
-        allocationSize = 1)
+            name           = "SEQUENCE_ANNOTATIONS_ID_SEQ",
+            sequenceName   = "ANNOTATIONS_ID_SEQ",
+            allocationSize = 1)
     @GeneratedValue(
-        strategy  = GenerationType.SEQUENCE,
-        generator = "SEQUENCE_ANNOTATIONS_ID_SEQ")
+            strategy  = GenerationType.SEQUENCE,
+            generator = "SEQUENCE_ANNOTATIONS_ID_SEQ")
     @Column(name = "id")
     public Integer getId() {
-        return id;
+        return this.id;
     }
 
-    public void setId(Integer id) {
+    public void setId(final Integer id) {
         this.id = id;
     }
 
     @OneToOne
     @JoinColumn(name = "range_id")
     public Range getRange() {
-        return range;
+        return this.range;
     }
 
-    public void setRange(Range range) {
+    public void setRange(final Range range) {
         this.range = range;
     }
 
     @OneToOne
     @JoinColumn(name = "attribute_id")
     public Attribute getAttribute() {
-        return attribute;
+        return this.attribute;
     }
 
-    public void setAttribute(Attribute attribute) {
+    public void setAttribute(final Attribute attribute) {
         this.attribute = attribute;
     }
 
+    @Transient
+    public AttributeKey getAttributeKey() {
+        return this.getAttribute().getKey();
+    }
+
     @OneToOne
     @JoinColumn(name = "position_id")
     public Position getPosition() {
-        return position;
+        return this.position;
     }
 
-    public void setPosition(Position position) {
+    public void setPosition(final Position position) {
         this.position = position;
     }
 
     @OneToOne
     @JoinColumn(name = "edge_id")
     public Edge getEdge() {
-        return edge;
+        return this.edge;
     }
 
-    public void setEdge(Edge edge) {
+    public void setEdge(final Edge edge) {
         this.edge = edge;
     }
 
     @OneToOne
     @JoinColumn(name = "type_id")
     public AnnotationType getType() {
-        return type;
+        return this.type;
     }
 
-    public void setType(AnnotationType type) {
+    public void setType(final AnnotationType type) {
         this.type = type;
     }
 }