+ *
+ * @example
+ *
+ * var addies, wanted, results;
+ *
+ * // Create your address book
+ * addies = new mw.Map();
+ *
+ * // This data could be coming from an external source (eg. API/AJAX)
+ * addies.set( {
+ * 'John Doe' : '10 Wall Street, New York, USA',
+ * 'Jane Jackson' : '21 Oxford St, London, UK',
+ * 'Dominique van Halen' : 'Kalverstraat 7, Amsterdam, NL'
+ * } );
+ *
+ * wanted = ['Dominique van Halen', 'George Johnson', 'Jane Jackson'];
+ *
+ * // You can detect missing keys first
+ * if ( !addies.exists( wanted ) ) {
+ * // One or more are missing (in this case: "George Johnson")
+ * mw.log( 'One or more names were not found in your address book' );
+ * }
+ *
+ * // Or just let it give you what it can
+ * results = addies.get( wanted, 'Middle of Nowhere, Alaska, US' );
+ * mw.log( results['Jane Jackson'] ); // "21 Oxford St, London, UK"
+ * mw.log( results['George Johnson'] ); // "Middle of Nowhere, Alaska, US"
+ *