getSysvarClockDecoder
Returns a decoder that you can use to decode a byte array representing the Clock sysvar's
account data to a SysvarClock.
Returns
FixedSizeDecoder<Readonly<{
epoch: bigint;
epochStartTimestamp: UnixTimestamp;
leaderScheduleEpoch: bigint;
slot: bigint;
unixTimestamp: UnixTimestamp;
}>, 40>