persistable sclass VectorOptimizedSSIList extends AbstractSSIList<AbstractSSI> {
  *() { init(); }
  *(Cl<? extends AbstractSSI> l) { super(l); }
  
  static VectorOptimizedSSIList alreadyOptimized(L<AbstractSSI> l) {
    new VectorOptimizedSSIList list;
    list.addAll(l);
    ret list;
  }
  
  @Override
  AbstractSSI importSSI(AbstractSSI ssi) {
    ret vectorizeSSIIfBeneficial(ssi.toSSI());
  }
  
  L<VectorSSI> vectorSSIs() { ret instancesOf VectorSSI(this); }
  L<SSI> directSSIs aka literalSSIs() { ret instancesOf SSI(this); }
  
  Percent percentageVectorized() {
    ret Percent.ratio(l(vectorSSIs()), l(this));
  }
}