def write_a_blip(index)
      schema  = 'http://schemas.openxmlformats.org/officeDocument/'
      xmlns_r = "#{schema}2006/relationships"
      r_embed = "rId#{index}"

      attributes = [
        ['xmlns:r', xmlns_r],
        ['r:embed', r_embed]
      ]

      @writer.empty_tag('a:blip', attributes)
    end
def write_a_blip(index)
      schema  = 'http://schemas.openxmlformats.org/officeDocument/'
      xmlns_r = "#{schema}2006/relationships"
      r_embed = "rId#{index}"

      attributes = [
        ['xmlns:r', xmlns_r],
        ['r:embed', r_embed]
      ]

      @writer.empty_tag('a:blip', attributes)
    end
Write the <a:blip> element.