fixes memcached bucket manager

memcached-driver/src/main/java/org/jnosql/diana/memcached/key/MemcachedBucketManager.java

@@ -29,6 +29,7 @@
 
 final class MemcachedBucketManager implements BucketManager {
 
+    private static final int NO_EXP = 0;
     private final MemcachedClient client;
     private final String bucketName;
 
@@ -37,25 +38,27 @@ final class MemcachedBucketManager implements BucketManager {
         this.bucketName = bucketName;
     }
 
+
+    @Override
+    public <K> void put(KeyValueEntity<K> entity) {
+        requireNonNull(entity, "entity is required");
+        put(entity.getKey(), entity.get());
+    }
+
+
     @Override
     public <K, V> void put(K key, V value) {
         requireNonNull(key, "key is required");
         requireNonNull(value, "value is required");
-        client.set(getKey(key), 0, value);
+        set(key, value, NO_EXP);
 
     }
 
-    @Override
-    public <K> void put(KeyValueEntity<K> entity) {
-        requireNonNull(entity, "entity is required");
-        put(getKey(entity.getKey()), entity.get());
-    }
-
     @Override
     public <K> void put(KeyValueEntity<K> entity, Duration ttl) {
         requireNonNull(entity, "entity is required");
         requireNonNull(ttl, "ttl is required");
-        client.set(getKey(entity.get()), (int) ttl.getSeconds(), entity.get());
+        set(entity.getKey(), entity.get(), (int) ttl.getSeconds());
     }
 
     @Override
@@ -108,4 +111,8 @@ public void close() {
     private <K> String getKey(K key) {
         return bucketName + ':' + key.toString();
     }
+
+    private void set(Object key, Object value, int exp) {
+        client.set(getKey(key), exp, value);
+    }
 }