Size
Knowing serialized size of the node is useful for preallocating byte-slice in advance. Signed-off-by: Evgeniy Stratonikov <evgeniy@nspcc.ru>
We use them quite frequently (consider children for a new branch node) and it is better to get rid of unneeded allocations. Signed-off-by: Evgeniy Stratonikov <evgeniy@nspcc.ru>