Fix for issue 1814 for dart:dom

client/dom/generated/src/frog/IDBCursor.dart

 
 class _IDBCursorJs extends _DOMTypeJs implements IDBCursor native "*IDBCursor" {
 
   static final int NEXT = 0;
 
   static final int NEXT_NO_DUPLICATE = 1;
 
   static final int PREV = 2;
 
   static final int PREV_NO_DUPLICATE = 3;
 
   final int direction;
 
   final _IDBKeyJs key;
 
   final _IDBKeyJs primaryKey;
 
   final _IDBAnyJs source;
 
-  void continueFunction([_IDBKeyJs key = null]) native;
+  void continueFunction([_IDBKeyJs key = null]) native '''
+if (key == null) return this['continue']();
+return this['continue'](key);
+''';
 
   _IDBRequestJs delete() native;
 
   _IDBRequestJs update(Dynamic value) native;
 }