message: Add TODO about keys copy.
diff: @@ -19,7 +19,7 @@ impl WalletIterator {
  pub fn new(storage_iter: Box<StorageIterator>, keys: &Keys) -> Self {
  WalletIterator {
  storage_iterator: storage_iter,
  - keys: keys.clone(),
  + keys: keys.clone() /* TODO FIXME: Avoid clone, especially for sensitive information. */,
  }
  }
  