getChildren of OffsetNode now returns unmodifiable list

Author: dabico

src/main/java/ch/usi/si/seart/treesitter/OffsetTreeCursor.java

@@ -5,6 +5,7 @@
 import lombok.experimental.FieldDefaults;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
 import java.util.function.Consumer;
@@ -125,7 +126,10 @@ public int getChildCount() {
         public List<Node> getChildren() {
             return node.getChildren().stream()
                     .map(OffsetNode::new)
-                    .collect(Collectors.toList());
+                    .collect(Collectors.collectingAndThen(
+                            Collectors.toList(),
+                            Collections::unmodifiableList
+                    ));
         }
 
         @Override