@Override
  protected void deserializeStateData(ProcedureStateSerializer serializer) throws IOException {
    super.deserializeStateData(serializer);
    SnapshotProcedureStateData data = serializer.deserialize(SnapshotProcedureStateData.class);
    this.snapshot = data.getSnapshot();
  }
A procedure used to take snapshot on tables.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/SnapshotProcedure.java