docs: def pad(self, file, size=6):
          """Group together as many records as possible to fit in the specified size
  
          Args:
              file (str): file path to read the records from.
              size (int): maximum size in MB that each group of records will be fitted to.
                  passing 0 means unlimited size.
  
          Returns:
              generator of records
          """
          buffer = ''
          for element in self.splitter.split(file):
              if _payload_size_within_limit(buffer + element, size):
                  buffer += element
              else:
                  tmp = buffer
                  buffer = element
                  yield tmp
          if _validate_payload_size(buffer, size):
              yield buffer