Model put returns old value

2 files changed, 3 insertions, 3 deletions

diff --git a/model-data/src/main/java/org/eclipse/viatra/solver/data/model/Model.java b/model-data/src/main/java/org/eclipse/viatra/solver/data/model/Model.java
index a19e4d5f..2b21e3e7 100644
--- a/model-data/src/main/java/org/eclipse/viatra/solver/data/model/Model.java
+++ b/model-data/src/main/java/org/eclipse/viatra/solver/data/model/Model.java
@@ -12,7 +12,7 @@ public interface Model extends Versioned{
         
         <K,V> V get(DataRepresentation<K,V> representation, K key);
         <K,V> Cursor<K,V> getAll(DataRepresentation<K,V> representation);
-        <K,V> void put(DataRepresentation<K,V> representation, K key, V value);
+        <K,V> V put(DataRepresentation<K,V> representation, K key, V value);
         <K,V> void putAll(DataRepresentation<K,V> representation, Cursor<K,V> cursor);
         <K,V> long getSize(DataRepresentation<K,V> representation);
         
diff --git a/model-data/src/main/java/org/eclipse/viatra/solver/data/model/internal/ModelImpl.java b/model-data/src/main/java/org/eclipse/viatra/solver/data/model/internal/ModelImpl.java
index 55ddfd3a..6d7f4e97 100644
--- a/model-data/src/main/java/org/eclipse/viatra/solver/data/model/internal/ModelImpl.java
+++ b/model-data/src/main/java/org/eclipse/viatra/solver/data/model/internal/ModelImpl.java
@@ -57,8 +57,8 @@ public class ModelImpl implements Model {
         }
 
         @Override
-        public <K, V> void put(DataRepresentation<K, V> representation, K key, V value) {
-                getMapValidateKey(representation, key).put(key, value);
+        public <K, V> V put(DataRepresentation<K, V> representation, K key, V value) {
+                return getMapValidateKey(representation, key).put(key, value);
         }
 
         @Override