clear

Clears the data of the MutableEventLog. This will not necessarily reset the acknowledged events, which will still act as a baseline for event insertions and appends.

Why use clear at all then, instead of creating a new MutableEventLog ?

Because keeping the acknowledged meta-data is sometimes useful when performing synchronization with multiple sites concurrently. We want to keep track of what we've already seen and dispatched to a central MutableEventLog or MutableHistory, but do not need to keep track of the actual body of the events that were already sent.