code: def line_spacing(self):
          
          lnSpc = self.lnSpc
          if lnSpc is None:
              return None
          if lnSpc.spcPts is not None:
              return lnSpc.spcPts.val
          return lnSpc.spcPct.val
docs: The spacing between baselines of successive lines in this paragraph.
          A float value indicates a number of lines. A |Length| value indicates
          a fixed spacing. Value is contained in `./a:lnSpc/a:spcPts/@val` or
          `./a:lnSpc/a:spcPct/@val`. Value is |None| if no element is present.