def _parse_sod_segment(self, fptr):
offset = fptr.tell() - <NUM_LIT:2><EOL>length = <NUM_LIT:0><EOL>return SODsegment(length, offset)<EOL>
Parse the SOD (start-of-data) segment.

        Parameters
        ----------
        fptr : file
            Open file object.

        Returns
        -------
        SODSegment
            The current SOD segment.