public void deleteSnapshot(SnapshotDescription snapshot) throws SnapshotDoesNotExistException, IOException {
// call coproc pre hook
MasterCoprocessorHost cpHost = master.getMasterCoprocessorHost();
if (cpHost != null) {
cpHost.preDeleteSnapshot(snapshot);
}
// check to see if it is completed
if (!isSnapshotCompleted(snapshot)) {
throw new SnapshotDoesNotExistException(snapshot);