basic get&set of Map properties works

src/Types/Map.js

@@ -0,0 +1,29 @@
+
+(function(){
+  class Map {
+    constructor (_model) {
+      this._model = _model;
+    }
+    *val () {
+      var transaction = yield "transaction";
+      var model = yield* transaction.getOperation(this._model);
+      if (arguments.length === 0) {
+        throw new Error("Implement this case!");
+      } else if (arguments.length === 1) {
+        return yield* Y.Struct.Map.get.call(transaction, model, arguments[0]);
+      } else {
+        return yield* Y.Struct.Map.set.call(transaction, model, arguments[0], arguments[1]);
+      }
+    }
+  }
+
+  Y.Map = function* YMap(){
+    if (this instanceof Y.AbstractOperationStore) {
+      var model = yield* Y.Struct.map.create.call(this);
+      return new Map(model);
+    } else {
+      throw new Error("Don't use `new` to create this type!");
+    }
+  };
+  Y.Map.Create = Map;
+})();

src/Types/Object.js

@@ -1,25 +0,0 @@
-
-(function(){
-  class Map {
-    constructor (_model) {
-      this._model = _model;
-    }
-    *val () {
-      var transaction = yield "transaction";
-      var model = transaction.getOperation(this._model);
-      if (arguments.length === 0) {
-        throw new Error("Implement this case!");
-      } else if (arguments.length === 1) {
-        return yield* this.Struct.Map.get.call(transaction, model, arguments[0]);
-      } else {
-        return yield* this.Struct.Map.set.call(transaction, model, arguments[0], arguments[1]);
-      }
-    }
-  }
-
-  Y.Map = function* YMap(){
-    var model = yield* this.Struct.map.create.call(this);
-    return new Map(model);
-  };
-  Y.Map.Create = Map;
-})();