func (pr *Progress) needSnapshotAbort() bool {
	return pr.State == ProgressStateSnapshot && pr.Match >= pr.PendingSnapshot
}
func (pr *Progress) needSnapshotAbort() bool {
	return pr.State == ProgressStateSnapshot && pr.Match >= pr.PendingSnapshot
}
// needSnapshotAbort returns true if snapshot progress's Match
// is equal or higher than the pendingSnapshot.