code: func CountBitmap(bitmap, sbit C.MMBitmapRef, args ...float32) int {
  	var tolerance C.float = 0.01
  	if len(args) > 0 {
  		tolerance = C.float(args[0])
  	}
  
  	count := C.count_of_bitmap(bitmap, sbit, tolerance)
  	return int(count)
  }
docs: // CountBitmap count of the bitmap