Job inheriting.

[Sin]

in the old 'eAthena' source, inheriting job was quite simple

 case JOB_EXAMPLE:
  class_ |= JOBL_THIRD;
 case JOB_GUNSLINGER:
  class_ |= MAPID_GUNSLINGER;
  break;

but now it's different in rAthena which I don't understand at all, can anyone help explain how the other classes inherit each other, and how I would make a custom class inherit another class's job mask, in this case, the example job inheriting the gunslinger map id.

Thanks.

Anyone knows how jobs are inherited from each other? Please I really don't understand the current method.