Which clock to compare events by. Defaults to
• Lamport: = "lamport"
Comparison according to Lamport clock, which is a logical clock, meaning it preserves causal order even when wall clocks on devices are off.
On the flip-side, for any two events where neither is a cause of the other, lamport-order may be different from timestamp-order, if the devices creating the events where disconnected from each other at the time.
• Timestamp: = "timestamp"
Comparison according to wall clock time logged at event creation. If the system clock on a device is wrong, the event's timestamp will also be wrong.