Adding a Popup object with a close() method on it.

front/src/Api/Events/ClosePopupEvent.ts

@@ -0,0 +1,11 @@
+import * as tg from "generic-type-guard";
+
+export const isClosePopupEvent =
+    new tg.IsInterface().withProperties({
+        popupId: tg.isNumber,
+    }).get();
+
+/**
+ * A message sent from the iFrame to the game to add a message in the chat.
+ */
+export type ClosePopupEvent = tg.GuardedType<typeof isClosePopupEvent>;