message: impl Iterator for Range
diff: @@ -29,4 +29,9 @@ impl Range {
  pub fn iter<'a>(&'a self) -> refpack::Iter<'a, BlockHash> { self.0.iter() }
  }
  -
  +impl Iterator for Range {
  + type Item = BlockHash;
  + fn next(&mut self) -> Option<Self::Item> {
  + self.0.pop_front()
  + }
  +}
  