def ref_beam_item
      item = DICOM::Item.new
      item.add(DICOM::Element.new(OBS_NUMBER, @number.to_s))
      item.add(DICOM::Element.new(REF_ROI_NUMBER, @number.to_s))
      item.add(DICOM::Element.new(ROI_TYPE, @type))
      item.add(DICOM::Element.new(ROI_INTERPRETER, @interpreter))
      return item
    end
def ref_beam_item
      item = DICOM::Item.new
      item.add(DICOM::Element.new(OBS_NUMBER, @number.to_s))
      item.add(DICOM::Element.new(REF_ROI_NUMBER, @number.to_s))
      item.add(DICOM::Element.new(ROI_TYPE, @type))
      item.add(DICOM::Element.new(ROI_INTERPRETER, @interpreter))
      return item
    end
Creates a Referenced Beam Sequence Item from the attributes of the Beam instance.

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