code: func (ml MetalLayer) SetMaximumDrawableCount(count int) {
  	e := C.MetalLayer_SetMaximumDrawableCount(ml.metalLayer, C.uint_t(count))
  	if e != nil {
  		panic(errors.New(C.GoString(e)))
  	}
  }
docs: // SetMaximumDrawableCount controls the number of Metal drawables in the resource pool
  // managed by Core Animation.
  //
  // It can set to 2 or 3 only. SetMaximumDrawableCount panics for other values.
  //
  // Reference: https://developer.apple.com/documentation/quartzcore/cametallayer/2938720-maximumdrawablecount.