message: early return is cleaner IMO
diff: @@ -43,8 +43,9 @@ where
  fn next(&mut self) -> Option<Self::Item> {
  if self.done {
  - None
  - } else {
  + return None;
  + }
  +
  match (self.req)(self.page_size, self.offset) {
  Ok(page) if page.items.is_empty() => {
  self.done = true;
  @@ -58,7 +59,6 @@ where
  }
  }
  }
  -}
  /// Helper to transform a `Result<Iterator<Item = T>, E>` into an `Iterator<Item
  /// = Result<T, E>>`.
  