def beam_item
      item = DICOM::Item.new
      item.add(DICOM::Element.new(ROI_COLOR, @color))
      s = DICOM::Sequence.new(CONTOUR_SQ)
      item.add(s)
      item.add(DICOM::Element.new(REF_ROI_NUMBER, @number.to_s))
      # Add Contour items to the Contour Sequence (one or several items per Slice):
      @slices.each do |slice|
        slice.contours.each do |contour|
          s.add_item(contour.to_item)
        end
      end
      return item
    end
def beam_item
      item = DICOM::Item.new
      item.add(DICOM::Element.new(ROI_COLOR, @color))
      s = DICOM::Sequence.new(CONTOUR_SQ)
      item.add(s)
      item.add(DICOM::Element.new(REF_ROI_NUMBER, @number.to_s))
      # Add Contour items to the Contour Sequence (one or several items per Slice):
      @slices.each do |slice|
        slice.contours.each do |contour|
          s.add_item(contour.to_item)
        end
      end
      return item
    end
Creates a Beam Sequence Item from the attributes of the Beam instance.

 @return [DICOM::Item] a beam sequence item