Create Promotion.java

Author: janbodnar

pitfalls/Promotion.java

@@ -0,0 +1,10 @@
+void main() {
+
+  byte x = 10;
+  byte y = 20;
+
+  var res = (Object) (x + y);
+
+  IO.println(res);
+  IO.println(res.getClass().getName());
+}