# File lib/compass/sass_extensions/functions/sprites.rb, line 59
  def sprite_file(map, sprite)
    sprite = convert_sprite_name(sprite)
    verify_map(map, "sprite")
    verify_sprite(sprite)
    if image = map.image_for(sprite.value)
      Sass::Script::String.new(image.relative_file)
    else
      missing_image!(map, sprite)
    end
  end