docs: def create_sequence_sites(chain, seq_site_length):
          """Create sequence sites using sequence ids.
  
          :param dict chain: Chain object that contains chemical shift values and assignment information.
          :param int seq_site_length: Length of a single sequence site.
          :return: List of sequence sites.
          :rtype: :py:class:`list`
          """
          seq_ids = sorted(list(chain.keys()), key=int)  # make sure that sequence is sorted by sequence id
          slices = [itertools.islice(seq_ids, i, None) for i in range(seq_site_length)]
          seq_site_ids = list(zip(*slices))
  
          sequence_sites = []
          for seq_site_id in seq_site_ids:
              seq_site = plsimulator.SequenceSite(chain[seq_id] for seq_id in seq_site_id)
              if seq_site.is_sequential():
                  sequence_sites.append(seq_site)
              else:
                  continue
  
          return sequence_sites