Number of individual NAKs received by the source transport (LBT-RM, LBT-RU).

- n (Int32)
- Statistics set index

Number of individual NAKs received by the source transport.

When a source transport receives a NAK from a receiver transport, it may
respond by re-transmitting the requested datagram, or it may send an
NCF. The NAKing receiver transport responds to the NCF by waiting (timeout
set by the transport's NAK suppress interval option, default 1000 ms), then
re-sending the NAK.
This method returns a value from the nth set of statistics
encapsulated within this object.