code: def _get_num_tokens_from_first_line(line: str) -> Optional[int]:
          
          fields = line.split(' ')
          if 1 <= len(fields) <= 2:
              try:
                  int_fields = [int(x) for x in fields]
              except ValueError:
                  return None
              else:
                  num_tokens = max(int_fields)
                  logger.info('Recognized a header line in the embedding file with number of tokens: %d',
                              num_tokens)
                  return num_tokens
          return None
docs: This function takes in input a string and if it contains 1 or 2 integers, it assumes the
          largest one it the number of tokens. Returns None if the line doesn't match that pattern.