Number of NAKs this source transport ignored and sent an NCF with reason
code "ignored" (LBT-RM only).

- n (Int32)
- Statistics set index

Number of NAKs this source transport ignored and sent an NCF with
reason code set to "ignored".

A source transport ignores a NAK for a datagram it has already recently
retransmitted. How "recently" is determined by the configuration option source
transport_lbtrm_ignore_interval (default 500ms). If this count is high, a
receiver transport may be having trouble receiving retransmissions, or the
ignore interval may be set too long.
This method returns a value from the nth set of statistics
encapsulated within this object.