static final record WidthAndHeightFinal(int width, int height) extends Meta is WidthAndHeight
  ifclass ByteIO , ByteIO endif {
  public int getWidth() { ret width; }
  public int getHeight() { ret height; }
  
  *(int wAndH) { this(wAndH, wAndH); }
  
  toString { ret n2(width) + "*" + n2(height) + " px"; }
  
  ifclass ByteHead
  public void readWrite(ByteHead head) {
    head.exchangeInt(l0 width, w -> width = w);
    head.exchangeInt(l0 height, h -> height = h);
  }
  endif
}

Began life as a copy of #1033637