enum TtlUpdateEvent {
  // required, default option
  OnCreate,
  // optional
  OnRead,
  OnWrite,
  OnReadWrite
}

enum TtlTimeCharacteristic {
  EVENT_TIME,
  PROCESSING_TIME
}

class TtlPolicy {
  TtlUpdateEvent ttlEvent;
  int ttl;
  TtlTimeCharacteristics ttlTimeCharacteristics;

  // ...
}

// ttl in sec
ttl = 5

// default TTL, using TtlPolicy.OnCreate
ttlPolicy1 = new TtlPolicy(ttl, TimeCharacteristic.EVENT_TIME)
// extended TTL, using TtlPolicy.OnCreate and TtlPolicy.onReadWrite
ttlPolicy2 = new TtlPolicy(ttl, TimeCharacteristic.PROCESSING_TIME, TtlEvent.OnReadWrite)

state1 = getRuntimeContext().getState(new ValueStateDescriptor<T>("x", ser, ttlPolicy1);
state2 = getRuntimeContext().getState(new ValueStateDescriptor<T>("y", ser, ttlPolicy2));