question: void incoming ( ) throws IOException { writeLine ( String . format ( "hello from %s" , hostId ) ) ; String line = readLine ( ) ; if ( networkTracing ) { logger . info ( "[{}] {}" , hostId , line ) ; } Matcher matcher = makeCallPattern . matcher ( line ) ; if ( matcher . find ( ) ) { makeCall = true ; fromMemberId = Integer . parseInt ( matcher . group ( 1 ) ) ; toMemberId = Integer . parseInt ( matcher . group ( 2 ) ) ; } else { matcher = requestCallBackPattern . matcher ( line ) ; if ( matcher . find ( ) ) { fromMemberId = Integer . parseInt ( matcher . group ( 1 ) ) ; toMemberId = Integer . parseInt ( matcher . group ( 2 ) ) ; } else { throw new IllegalStateException ( "Invalid message: " + line ) ; } } }
target:  Gets the calling member ids.