def add_image(image)
      raise ArgumentError, "Invalid argument 'image'. Expected Image, got #{image.class}." unless image.is_a?(Image)
      @images << image unless @frame.image(image.uid)
      @slices[image.uid] = image.pos_slice
      @image_positions[image.pos_slice.round(2)] = image
      @sop_uids[image.pos_slice] = image.uid
      # The link between image uid and image instance is kept in the Frame, instead of the ImageSeries:
      @frame.add_image(image) unless @frame.image(image.uid)
    end
def add_image(image)
      raise ArgumentError, "Invalid argument 'image'. Expected Image, got #{image.class}." unless image.is_a?(Image)
      @images << image unless @frame.image(image.uid)
      @slices[image.uid] = image.pos_slice
      @image_positions[image.pos_slice.round(2)] = image
      @sop_uids[image.pos_slice] = image.uid
      # The link between image uid and image instance is kept in the Frame, instead of the ImageSeries:
      @frame.add_image(image) unless @frame.image(image.uid)
    end
Adds an Image to this ImageSeries.

 @param [Image] image an image instance to be associated with this image series