def write_nv_sp_pr(index, shape)
      attributes = []
      attributes << ['txBox', 1] if shape.tx_box

      @writer.tag_elements('xdr:nvSpPr') do
        write_c_nv_pr(shape.id, "#{shape.type} #{index}")

        @writer.tag_elements('xdr:cNvSpPr', attributes) do
          @writer.empty_tag('a:spLocks', [ [:noChangeArrowheads, '1'] ])
        end
      end
    end
def write_nv_sp_pr(index, shape)
      attributes = []
      attributes << ['txBox', 1] if shape.tx_box

      @writer.tag_elements('xdr:nvSpPr') do
        write_c_nv_pr(shape.id, "#{shape.type} #{index}")

        @writer.tag_elements('xdr:cNvSpPr', attributes) do
          @writer.empty_tag('a:spLocks', [ [:noChangeArrowheads, '1'] ])
        end
      end
    end
Write the <xdr:NvSpPr> element.