code: public EntryBuffer append(Entry entry) {
      int offset = offset(entry.getIndex());
      Entry oldEntry = buffer[offset];
      buffer[offset] = entry.acquire();
      if (oldEntry != null) {
        oldEntry.release();
      }
      return this;
    }
docs: Appends an entry to the buffer.
  
  @param entry The entry to append.
  @return The entry buffer.