message: Using  instead of u64.
diff: @@ -224,8 +224,8 @@ fn index_documents(
  fn apply_deletes(
  segment: &Segment,
  mut delete_cursor: &mut DeleteCursor,
  - doc_opstamps: &[u64],
  - last_docstamp: u64,
  + doc_opstamps: &[Opstamp],
  + last_docstamp: Opstamp,
  ) -> Result<Option<BitSet<u32>>> {
  if delete_cursor.get().is_none() {
  // if there are no delete operation in the queue, no need
  @@ -750,7 +750,7 @@ impl IndexWriter {
  mod tests {
  use super::super::operation::UserOperation;
  - use crate::collector::TopDocs;
  + use crate::collector::TopDocs;gi
  use crate::directory::error::LockError;
  use crate::error::*;
  use crate::indexer::NoMergePolicy;
  