Number of datagrams received (LBT-RM only)

- n (Int32)
- Statistics set index

Number of datagrams received.

Depending on batching settings, a single LBT-RM datagram may contain one or
more messages, or a fragment of a larger message. With LBT-RM, larger messages
are split into fragment sizes limited by configuration option
transport_lbtrm_datagram_max_size (default 8KB).
This method returns a value from the nth set of statistics
encapsulated within this object.