public boolean containsAll(Collection<Taxon> taxa){
  for (  Taxon taxon : taxa) {
    if (!taxa.contains(taxon)) {
      return false;
    }
  }
  return true;
}

public boolean containsAll ( Collection < Taxon > taxa ) { for ( Taxon taxon : taxa ) { if ( ! taxa . contains ( taxon ) ) { return false ; } } return true ; }
returns true if taxonlist is a subset of the taxa in this taxa .
