message: More tests for BlockHeadersBatchId
diff: @@ -2903,7 +2903,7 @@ mod tests {
  ProtocolVersion::V1_0_0,
  false,
  EraId::new(100),
  - vec![],
  + std::iter::empty(),
  );
  let trusted_header = trusted_block.take_header();
  @@ -2911,9 +2911,38 @@ mod tests {
  let id = BlockHeadersBatchId::from_known(&trusted_header, batch_size);
  - assert_eq!(BlockHeadersBatchId::new(99, 90), id);
  + assert_eq!(
  + BlockHeadersBatchId::new(99, 90),
  + id,
  + "expected batch of proper length and skipping trusted height"
  + );
  let id_saturated = BlockHeadersBatchId::from_known(&trusted_header, 1000);
  - assert_eq!(BlockHeadersBatchId::new(99, 0), id_saturated);
  + assert_eq!(
  + BlockHeadersBatchId::new(99, 0),
  + id_saturated,
  + "expect batch towards Genesis"
  + );
  +
  + let trusted_last = Block::random_with_specifics(
  + &mut rng,
  + EraId::new(0),
  + 1,
  + ProtocolVersion::V1_0_0,
  + false,
  + EraId::new(100),
  + std::iter::empty(),
  + );
  +
  + let trusted_last_header = trusted_last.take_header();
  +
  + let id_last = BlockHeadersBatchId::from_known(&trusted_last_header, batch_size);
  + assert_eq!(
  + BlockHeadersBatchId::new(0, 0),
  + id_last,
  + "expected batch that saturates towards Genesis and doesn't include known height"
  + );
  + }
  +
  }
  }
  