many thanks for answer
however if you could confirm that i understand correctly, i'd be grateful :
if (context.getSubscribedInstruments().contains( Instrument.XAGUSD )) {
engine.submitorder(//...
}
so
context.getSubscribedInstruments().contains( Instrument.XAGUSD )
will return false if xagusd is not available for trading at the time of the call of the method and true if it is with almost no chance to see the order being rejected
nb: i obviously took xagusd as example because that instrument if offline many time every day