this.actorContext = Preconditions.checkNotNull(actorContext);
this.leader = Preconditions.checkNotNull(leader);
this.transaction = Preconditions.checkNotNull(transaction);
this.modification = Preconditions.checkNotNull(modification);
this.actorContext = Preconditions.checkNotNull(actorContext);
this.leader = Preconditions.checkNotNull(leader);
this.transaction = Preconditions.checkNotNull(transaction);
this.modification = Preconditions.checkNotNull(modification);