public abstract void WriteText(
     string text,
     PKBrush brush,
     PKFont font,
     PKHAlign align,
     int x, int y, int w, int h);
 public abstract void FillRectangle(PKBrush brush, int x, int y, int w, int h);
 public abstract void FillEllipse(PKBrush brush, int x, int y, int w, int h);
 public abstract void FillRectangle(PKBrush brush, int x, int y, int w, int h, PKRectangleCorners corners);