persistable asclass AbstractSSI is G2Drawable, HasBounds, SizeInInts, StringIO, INumberOfPixels {
  // Color in 15 bit
  settable short hi15color;
  
  Color color() {
    ret main hi15color(hi15color);
  }
  
  selfType color(Color color) {
    ret hi15color(colorToHi15(color));
  }
  
  S colorToString() {
    ret lower(colorToHex(color()));
  }
  
  abstract SSI toSSI aka render();
  
  void copyAbstractSSI(AbstractSSI dest) {
    dest.hi15color(hi15color);
  }
  
  double compressibility() {
    ret doubleRatio(numberOfPixels(), sizeInInts());
  }
}