docs: @SuppressWarnings("unchecked")
    public static <V extends NumberVector> NumberVector.Factory<V> guessFactory(SimpleTypeInformation<V> in) {
      NumberVector.Factory<V> factory = null;
      if(in instanceof VectorTypeInformation) {
        factory = (NumberVector.Factory<V>) ((VectorTypeInformation<V>) in).getFactory();
      }
      if(factory == null) {
        // FIXME: hack. Add factories to simple type information, too?
        try {
          Field f = in.getRestrictionClass().getField("FACTORY");
          factory = (NumberVector.Factory<V>) f.get(null);
        }
        catch(Exception e) {
          LoggingUtil.warning("Cannot determine factory for type " + in.getRestrictionClass(), e);
        }
      }
      return factory;
    }