Added toTree with joined keys

Author: JanHolger

src/main/java/org/javawebstack/abstractdata/AbstractArray.java

@@ -319,6 +319,10 @@ public Map<String[], Object> toTree() {
         return object().toTree();
     }
 
+    public Map<String, Object> toTree(String keySeparator) {
+        return object().toTree(keySeparator);
+    }
+
     public AbstractElement clone() {
         AbstractArray array = new AbstractArray();
         forEach(e -> array.add(e.clone()));

src/main/java/org/javawebstack/abstractdata/AbstractObject.java

@@ -233,6 +233,12 @@ public Map<String[], Object> toTree() {
         return tree;
     }
 
+    public Map<String, Object> toTree(String keySeparator) {
+        Map<String, Object> tree = new HashMap<>();
+        toTree().forEach((k, v) -> tree.put(String.join(keySeparator, k), v));
+        return tree;
+    }
+
     public Set<String> keys() {
         return entries.keySet();
     }