Get the KERNINGRECORD structure.

def _get_struct_kerningrecord(self, font_flags_wide_codes):
        """Get the KERNINGRECORD structure."""
        getter = unpack_ui16 if font_flags_wide_codes else unpack_ui8
        data = {}
        data['FontKerningCode1'] = getter(self._src)
        data['FontKerningCode2'] = getter(self._src)
        data['FontKerningAdjustment'] = unpack_si16(self._src)
        return data