Add existing to tracked

node_modules/@cesium/engine/Source/Scene/MapMode2D.js

@@ -0,0 +1,28 @@
+// @ts-check
+
+/**
+ * Describes how the map will operate in 2D.
+ *
+ * @enum {number}
+ */
+const MapMode2D = {
+  /**
+   * The 2D map can be rotated about the z axis.
+   *
+   * @type {number}
+   * @constant
+   */
+  ROTATE: 0,
+
+  /**
+   * The 2D map can be scrolled infinitely in the horizontal direction.
+   *
+   * @type {number}
+   * @constant
+   */
+  INFINITE_SCROLL: 1,
+};
+
+Object.freeze(MapMode2D);
+
+export default MapMode2D;