code: def filter_known_searchspace(elements, seqtype, lookup, ns, ntermwildcards,
                               deamidation):
      
      for element in elements:
          seq_is_known = False
          for seq in get_seqs_from_element(element, seqtype, ns, deamidation):
              if lookup.check_seq_exists(seq, ntermwildcards):
                  seq_is_known = True
                  break
          if seq_is_known:
              formatting.clear_el(element)
          else:
              yield formatting.string_and_clear(element, ns)
docs: Yields peptides from generator as long as their sequence is not found in
      known search space dict. Useful for excluding peptides that are found in
      e.g. ENSEMBL or similar