code: def _merge_cluster(old, new):
      
      logger.debug("_merge_cluster: %s to %s" % (old.id, new.id))
      logger.debug("_merge_cluster: add idls %s" % old.loci2seq.keys())
      for idl in old.loci2seq:
          # if idl in new.loci2seq:
          #    new.loci2seq[idl] = list(set(new.loci2seq[idl] + old.loci2seq[idl]))
          # new.loci2seq[idl] = old.loci2seq[idl]
          new.add_id_member(old.loci2seq[idl], idl)
      return new
docs: merge one cluster to another