public int getFlowAt ( Direction direction ) { switch ( direction ) { case E : return eFlow ; case W : return wFlow ; case N : return nFlow ; case S : return sFlow ; case EN : return enFlow ; case NW : return nwFlow ; case WS : return wsFlow ; case SE : return seFlow ; default : throw new IllegalArgumentException ( ) ; } }
Get the value of the flow in one of the surrounding direction .