code: def get_record(self, record_num):
          
          for chunk in self.chunks():
              first_record = chunk.log_first_record_number()
              last_record = chunk.log_last_record_number()
              if not (first_record <= record_num <= last_record):
                  continue
              for record in chunk.records():
                  if record.record_num() == record_num:
                      return record
          return None
docs: Get a Record by record number.
  
          @type record_num:  int
          @param record_num: The record number of the the record to fetch.
          @rtype Record or None
          @return The record request by record number, or None if the
            record is not found.