code: private boolean acknowledgePort( Application application, Instance instance, String exportedVariableName ) {
  
  		boolean acknowledged = false;
  		String value = instance.overriddenExports.get( exportedVariableName );
  		if( value != null ) {
  
  			// If there is an overridden value, use it
  			this.logger.fine( "Acknowledging random port value for " + exportedVariableName + " in instance " + instance + " of " + application );
  			Integer portValue = Integer.parseInt( value );
  			InstanceContext ctx = findAgentContext( application, instance );
  
  			List<Integer> associatedPorts = this.agentToRandomPorts.get( ctx );
  			if( associatedPorts == null ) {
  				associatedPorts = new ArrayList<> ();
  				this.agentToRandomPorts.put( ctx, associatedPorts );
  			}
  
  			// Verify it is not already used.
  			// And cache it so that we do not pick it up later.
  			if( associatedPorts.contains( portValue )) {
  				this.logger.warning( "Random port already used! Failed to acknowledge/restore " + exportedVariableName + " in instance " + instance + " of " + application );
  				acknowledged = false;
  
  			} else {
  				associatedPorts.add( portValue );
  				acknowledged = true;
  			}
  		}
  
  		return acknowledged;
  	}
docs: If the instance already has a value (overridden export) for a random variable, then use it.
  <p>
  Basically, we do not have to define an overridden export.
  We only have to update the cache to not pick up the same port later.
  </p>
  
  @param application the application
  @param instance the instance
  @param exportedVariableName the name of the exported variable
  @return