question: public void registerPlayerObserver ( PlayerEventsObserver observer , boolean replyImmediately ) { if ( this . connection == null ) return ; playerEventsObservers . add ( observer ) ; if ( replyImmediately ) replyWithLastResult ( observer ) ; if ( playerEventsObservers . size ( ) == 1 ) { if ( connection . getProtocol ( ) == HostConnection . PROTOCOL_TCP ) { connection . registerPlayerNotificationsObserver ( this , checkerHandler ) ; connection . registerSystemNotificationsObserver ( this , checkerHandler ) ; connection . registerInputNotificationsObserver ( this , checkerHandler ) ; checkerHandler . post ( tcpCheckerRunnable ) ; } else { checkerHandler . post ( httpCheckerRunnable ) ; } } }
target:  Registers a new observer that will be notified about player events