question: public SharedDataIteratorSource ( Object identifier , ISourceDataIteratorProvider < T > sourceDataIteratorProvider , long timeToLive ) { if ( sourceDataIteratorProvider == null ) throw new IllegalArgumentException ( "sourceDataIteratorProvider cannot be null" ) ; _identifier = identifier ; _sourceDataIteratorProvider = sourceDataIteratorProvider ; _timeToLive = timeToLive ; _createdTime = SystemTime . timeMillis ( ) ; }
target:  Construct a new source