code: def _parse_sod_segment(self, fptr):
          
          offset = fptr.tell() - 2
          length = 0
  
          return SODsegment(length, offset)
docs: Parse the SOD (start-of-data) segment.
  
          Parameters
          ----------
          fptr : file
              Open file object.
  
          Returns
          -------
          SODSegment
              The current SOD segment.