question: @ VisibleForTesting public static boolean sendToTMaster ( String command , String topologyName , SchedulerStateManagerAdaptor stateManager , NetworkUtils . TunnelConfig tunnelConfig ) { LOG . fine ( "Fetching TMaster location for topology: " + topologyName ) ; TopologyMaster . TMasterLocation location = stateManager . getTMasterLocation ( topologyName ) ; if ( location == null ) { LOG . severe ( "Failed to fetch TMaster Location for topology: " + topologyName ) ; return false ; } LOG . fine ( "Fetched TMaster location for topology: " + topologyName ) ; String url = String . format ( "http://%s:%d/%s?topologyid=%s" , location . getHost ( ) , location . getControllerPort ( ) , command , location . getTopologyId ( ) ) ; try { URL endpoint = new URL ( url ) ; LOG . fine ( "HTTP URL for TMaster: " + endpoint ) ; return sendGetRequest ( endpoint , command , tunnelConfig ) ; } catch ( MalformedURLException e ) { throw new RuntimeException ( "Invalid URL for tmaster endpoint: " + url , e ) ; } }
target:  Communicate with TMaster with command