ClosedRowPolicy does not support DDR3

[LoveLonelyTime]

Hi,

I'm trying to simulate DDR3. But I get an error:

terminate called after throwing an instance of 'std::out_of_range'
  what():  unordered_map::at
Aborted

Finally, I notice that ClosedRowPolicy requires bankgroup. But bankgroup is first introduced by DDR4.

Currently, DDR3 simulation can only use OpenRowPolicy.

Thanks.