docs: def get_sequence_alignment_strings_as_html(self, pdb_list = [], reversed = False, width = 80, line_separator = '\n', extra_tooltip_class = ''):
          '''Takes a list, pdb_list, of pdb names e.g. ['Model', 'Scaffold', ...] with which the object was created.
              Using the first element of this list as a base, get the sequence alignments with chains in other members
              of the list. For simplicity, if a chain in the first PDB matches multiple chains in another PDB, we only
              return the alignment for one of the chains. If pdb_list is empty then the function defaults to the object's
              members.
  
              Returns HTML for the sequence alignments and an empty string if no alignments were made.'''
  
          raise Exception('Re-implement using the equivalence classes.')
  
          sequence_alignment_printer_tuples = self.get_sequence_alignment_printer_objects(pdb_list = pdb_list, reversed = reversed, width = width, line_separator = line_separator)
          if not sequence_alignment_printer_tuples:
              return ''
          html = []
          for sequence_alignment_printer_tuple in sequence_alignment_printer_tuples:
              primary_pdb_chain = sequence_alignment_printer_tuple[0]
              sap = sequence_alignment_printer_tuple[1]
              html.append(sap.to_html(reversed = reversed, width = width, line_separator = line_separator, extra_tooltip_class = extra_tooltip_class))
  
          return '\n'.join(html)