Initial work on Nucleus parity merge

Packages/ohif-viewerbase/client/lib/classes/metadata/Metadata.js

@@ -0,0 +1,40 @@
+
+/**
+ * Constants
+ */
+
+const STRING = 'string';
+const NUMBER = 'number';
+const FUNCTION = 'function';
+
+export class Metadata {
+
+    /**
+     * Constructor and Instance Methods
+     */
+
+    constructor(data) {
+        this._data = data;
+    }
+
+    getData() {
+        return this._data;
+    }
+
+    /**
+     * Static Methods
+     */
+
+    static isValidUID(uid) {
+        return typeof uid === STRING && uid.length > 0;
+    }
+
+    static isValidIndex(index) {
+        return typeof index === NUMBER && index >= 0 && (index | 0) === index;
+    }
+
+    static isValidCallback(callback) {
+        return typeof callback === FUNCTION;
+    }
+
+}