Optional
expectedOptional
keyWhether to use little endian when converting a uint32 key to a byte array.
ndn-ind behaves differently on big endian and little endian machines, https://github.com/operantnetworks/ndn-ind/blob/dd934a7a5106cda6ea14675554427e12df1ce18f/src/lite/util/crypto-lite.cpp#L114 This must be set to match other peers.
Expected number of IBLT entries, i.e. expected number of updates in a sync cycle.