Return the long int value contained in the *value_offset* field of
        this entry. Only supports single values at present.

def _parse_value(cls, stream_rdr, offset, value_count, value_offset):
        """
        Return the long int value contained in the *value_offset* field of
        this entry. Only supports single values at present.
        """
        if value_count == 1:
            return stream_rdr.read_long(offset, 8)
        else:  # pragma: no cover
            return 'Multi-value long integer NOT IMPLEMENTED'