var image/color.AlphaModel

3 uses

	image/color (current package)
		color.go#L170: 	AlphaModel   Model = ModelFunc(alphaModel)

	image
		image.go#L620: func (p *Alpha) ColorModel() color.Model { return color.AlphaModel }
		image.go#L653: 	p.Pix[i] = color.AlphaModel.Convert(c).(color.Alpha).A